WO2016044225A1

WO2016044225A1 - Highly transparent films comprising holographic optical elements useful for reducing solar heating

Info

Publication number: WO2016044225A1
Application number: PCT/US2015/050116
Authority: WO
Inventors: Peng Wang
Original assignee: Nitto Denko Corporation
Priority date: 2014-09-16
Filing date: 2015-09-15
Publication date: 2016-03-24

Abstract

Described herein are transparent composites comprising holographic optical elements which are useful for reducing solar heating. The heat blocking transparent composite comprises at least one holographic optical element and a transparent waveguide substrate, wherein said transparent waveguide substrate having a top surface for receipt of solar radiation, a bottom surface, and at least one edge surface; and wherein the at least one holographic optical element is disposed on a surface of the transparent waveguide substrate, and wherein the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out the edge or top surfaces of the heat blocking transparent composite. In some embodiments the system may also comprise luminescent wavelength conversion elements. In some embodiments the system may also comprise UV absorbing elements.

Description

HIGHLY TRANSPARENT FILMS COMPRISING HOLOGRAPHIC OPTICAL ELEMENTS USEFUL FOR REDUCING SOLAR HEATING

Inventor:

Peng Wang

FIELD OF THE DISCLOSURE

[1] The present disclosure generally relates to highly transparent composites comprising holographic optical elements which are useful for reducing solar heating.

BACKGROUND OF THE DISCLOSURE

Description of the Related Art

[2] With the recent increase in environment and energy-related issues, the needs for energy-saving industrial products has drawn a significant amount of interest in recent years. Since it generally costs from three to six times more to cool a building one degree than to heat it by the same amount (depending on the amount of glass used), the use of an exterior glass which will reduce the amount of solar radiation entering a building can provide substantial savings since less air conditioning equipment is required and its operation is less costly. Therefore, glass and film are desired for effectively reducing heat load in buildings and automobiles due to sunlight. In order to reduce heat load due to sunlight, it is necessary to prevent transmission of sunlight rays falling within any of the ultraviolet (UV), visible, or the infrared (IR) range of the sunlight spectrum. In particular, windowpanes for automobiles are required to have high transmittance of visible light from the safety viewpoint, and are additionally required to have a high level of heat shielding.

[3] Glass with heat shielding capabilities have traditionally fallen into either two categories: reflective glass or tinted glass. Tinted glass is generally made by adding metals such as iron, cobalt, and nickel to the molten glass during production. This method of producing colored glass is time consuming and wasteful in that when a different color of glass is desired, a four or five-day run of glass must be discarded while the change is made and the new batch stabilized. Also, large quantities of different colors and types of glass must be inventoried. In addition, although tinted glass does reduce glare, it also absorbs heat (including solar radiation), and the absorbed heat is reradiated from both sides of the glass. Therefore, a greater amount of heat is allowed to pass through the glass than with coated glass.

[4] Coated or reflective glass is provided with a thin film of a reflective substance on one of its surfaces. The thin film reflects the radiation much more effectively than tinted glass. Gold, copper, and their alloys are particularly effective as thin film coatings because they reduce transmittance in the infra-red range significantly. However, a durable coating of these materials, which will not rub or wear off the glass sheet, has not been achieved without using an intermediate layer of an adhesive material. Most companies sell coated glass only in double glazed (two panes separated by an air space) and in laminated forms. U.S. Patent No. 3,798,146 discloses a transparent article having reduced radiation transmittance which comprises a body of transparent glassy siliceous material having a smooth continuous surface and a continuous intermediate layer sputter-coated on the continuous surface to a thickness of from 10 to 200 A. The intermediate layer being a metal selected from the group consisting of molybdenum, titanium, chromium, tungsten, tantalum, and their alloys, and a continuous film sputter-coated on the continuous intermediate layer to a thickness of from 100 to 500 A., the film being of a metal selected from the group consisting of gold, gold-base alloys, copper, and copper-base alloys. U.S. Patent Application No. 201 1/0187973 discloses a heat shield comprising a first light-reflective layer, having a reflectance peak both in a wavelength range of from 400 nm to less than 850 nm and in a wavelength range of from more than 850 nm to 1300 nm and satisfying C>A>B. "A" meaning the maximum reflectance in the wavelength range of from 400 nm to less than 850 nm; "B" meaning the reflectance at a wavelength of 850 nm; "C" meaning the maximum reflectance in the wavelength range of from more than 850 nm to 1300 nm; and "B" is equal to or less than 50%.

[5] One of the most significant problems with both coated glass and colored glass is that the light transmittance is inversely proportional to the glass's ability to the heat shield. For instance, as the thickness of the coating is increased on the coated glass, both the heat transmittance and the light transmittance are reduced. Additionally, reflective metallic films may also block electromagnetic waves, causing a disruption of use in mobile telephones and the like or, when used in automobiles, causing a problem in electronic toll collection (ETC).

[6] More recent approaches have utilized other organic or liquid crystal materials to provide reflectivity to reduce solar heat transmittance through windows. U.S. Patent No. 8,102,586 discloses an automatic electronic window shading (tinting) system for houses and transport vehicles such as automobiles, RV's, trains, boats and the like, to provide shading for people and to protect them from exposure to harmful direct sunlight through the windows with display elements and light (photocell/photovoltaic) sensors. The system comprises liquid crystal, electrochromic, suspended particle device (SPD), or NanoChromics™ display (NCD) element attached to a part of a transparent body (such as the windows) and a liquid crystal, electrochromic, suspended particle device (SPD), or NanoChromics™ display (NCD) controlling semiconductor element controlling the operation of the display element. U.S. Patent Application No. 201 1 /0181820 discloses an infrared light reflecting plate which uses two pairs of light-reflective layers each formed of fixed cholesteric, liquid-crystal having an opposite optical rotation to each other (that is, having a right optical rotation or a left optical rotation), and that are not always required to be neighbor to each other or always required to be formed on the surface of one and the same substrate. The system reflects only infrared light and is therefore limited in its ability to block solar heat.

SUMMARY OF THE DISCLOSURE

[7] Described herein are heat blocking transparent composites comprising at least one holographic optical element and a transparent waveguide substrate. The holographic optical element and the transparent waveguide substrate of the heat blocking transparent composite are transparent such that they provide little to no visibility distortion and makes the film highly useful for window-based building or vehicle applications. In some embodiments, the transparent waveguide substrate comprises a major top surface for receipt of solar radiation, a bottom surface and at least one edge surface. In some embodiments, the at least one holographic optical element is disposed on a surface of the transparent waveguide substrate, wherein the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out the edge or top surfaces of the heat blocking transparent composite. In some embodiments, the heat blocking transparent composite is transparent in at least one viewing angle. In some embodiments, the heat blocking transparent composites are windows.

[8] The heat blocking transparent composite comprises a holographic optical element and a transparent waveguide substrate, wherein said transparent waveguide substrate has a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface; and wherein the holographic optical element is disposed on a surface of the transparent waveguide substrate, and wherein the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out the edge or top surfaces of the heat blocking transparent composite. In some embodiments, the system may also comprise luminescent wavelength conversion elements. In some embodiments, the system may also comprise UV absorbing elements.

[9] In some embodiments, the diffractive structures are the same across the length of the holographic optical element. In some embodiments, the diffractive structures continuously vary across the length of the holographic optical element. In some embodiments, the holographic optical element is configured with multiple diffractive structures. In some embodiments, the diffractive structures of the holographic optical element vary throughout the length of the holographic optical element, such that light incident on one side of the holographic optical element is diffracted at a different angle than the light incident on a different side of the holographic optical element. In some embodiments, the diffractive structures of the holographic optical element are continuously varying throughout the length of the holographic optical element.

[10] In some embodiments, the holographic optical element is configured to diffract photons at a different angle depending on the incident wavelength.

[11 ] The heat blocking transparent composite may be configured to be transparent at a variety of viewing angles depending on the application and/or location of the window in the building or vehicle, and/or the longitudinal location of the building. In some embodiments of the heat blocking transparent composite, the composite is transparent for a viewing angle of 0 degrees (i.e., the composite is transparent when looking straight through the window as illustrated in FIG. 1 ), or a viewing angle of about +20 degrees to about -20 degrees; about +40 degrees to about -40 degrees; about +60 degrees to about -60 degrees; about +90 degrees to about -90 degrees; about +20 degrees to about -90 degrees; or about +40 degrees to about -90 degrees from horizontal, or from normal to the top surface of the transparent waveguide substrate.

[12] In order for the heat blocking transparent composite to be applicable to window based applications, it may be helpful for the composite to be sufficiently transparent to provide undistorted viewing of the scenery through the window. The transmittance of visible light (wavelengths of light between 400 nm and 700 nm) through the composite is a good indicator of transparency. In some embodiments of the heat blocking transparent composite, the composite has a transmittance in at least one viewing angle of at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, and/or at least 90% for wavelengths of light between about 400 nm and 700 nm.

[13] In some embodiments, the heat blocking transparent composite is a window. In some embodiments, the window may be glass and/or polymer.

[14] In some embodiments, the window may be placed vertically in a building. In some embodiments, the holographic optical element is configured to diffract light incident on the system at angles of greater than about +70 degrees, about +50 degrees, about +30 degrees, or about +15 degrees from the horizontal, or from normal to the top surface of the transparent waveguide substrate.

[15] In some embodiments, the window may be placed horizontally (such as a sky light in a building or vehicle), in which case the holographic optical element(s) may be configured based on the desired viewing angle and/or the optimal heat blocking properties.

[16] In some embodiments, a luminescent material is incorporated into the heat blocking transparent composite to further enhance the solar heat blocking effect. In some embodiments, the luminescent material absorbs UV photons and converts these photons into visible wavelengths. [17] In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range and re-emit those photons at a different wavelength, wherein the re-emitted photons are internally reflected and refracted within the transparent waveguide substrate until they reach the edge surfaces where they can escape. In some embodiments, the transparent waveguide substrate comprises a single wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and at least one luminescent material. In some embodiments, the transparent waveguide substrate comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and a luminescent material. In some embodiments, the wavelength conversion layer or layers may be placed in between glass or polymer plates, wherein the glass or polymer plates also act to internally reflect and refract photons towards the edge surface. In some embodiments, the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also acts to internally reflect and refract photons towards the edge surface.

[18] The heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, as described herein, may include additional layers. For example, the film may comprise an adhesive layer in between the holographic optical element and transparent waveguide substrate. In some embodiments, the system may also comprise additional glass or polymer layers. In some embodiments, the additional glass or polymer layers may be incorporated into the transparent waveguide substrate, on the outside of a wavelength conversion layer to protect it from environmental elements. In some embodiments, additional glass or polymer layers may be used which encapsulate the holographic optical elements, or may be placed on top of the wavelength conversion layer. The glass or polymer layers may be configured to protect and prevent oxygen and moisture penetration into the wavelength conversion layer. In some embodiments, the glass or polymer layers may be used to internally refract or reflect photons that are emitted from the holographic optical element. In some embodiments, the system may further comprise a polymer layer comprising a UV absorber, configured to prevent harmful high energy photons from transmitting through the window into the building or vehicle and/or contacting the wavelength conversion layer. In some embodiments, it may also be possible to combine layers to optimize different advantages together into one device.

[19] The heat blocking transparent composite may further comprise a photovoltaic or solar cell. The heat blocking transparent composite may be configured for different types of solar energy conversion devices. In some embodiments of the heat blocking transparent composite, the photovoltaic cell is attached to the edge surface of the heat blocking transparent composite, and the photovoltaic cell absorbs a portion of the light that is diffracted by the holographic optical element. In some embodiments, the solar energy conversion device is selected from the group consisting of a silicon-based device, a ll l-V or ll-VI PN junction device, a Copper-Indium-Gallium-Selenium (CIGS) thin film device, an organic sensitizer device, an organic thin film device, or a Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) thin film device. In some embodiments, the photovoltaic device or solar cell may be an amorphous Silicon (a-Si) solar cell. In some embodiments, the photovoltaic device or solar cell comprises a microcrystalline Silicon (μο-Si) solar cell. In some embodiments, the photovoltaic device or solar cell may be a crystalline Silicon (c-Si) solar cell.

[20] In some embodiments, the heat blocking transparent composite does not include a photovoltaic or solar cell.

[21 ] These and other embodiments are described in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

[22] FIG. 1 illustrates the viewing angle of an embodiment of a heat blocking transparent composite.

[23] FIG. 2 shows a schematic of an embodiment of the heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate. [24] FIG. 3 shows a schematic of an embodiment of the heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate.

[25] FIG. 4 shows a schematic of an embodiment of the heat blocking transparent composite comprising a holographic optical element, a transparent waveguide substrate, and a wavelength conversion layer.

[26] FIG. 5 shows a schematic of an embodiment of the heat blocking transparent composite comprising a holographic optical element, a transparent waveguide substrate, a wavelength conversion layer, and a solar energy conversion device.

[27] FIG. 6 shows the temperature of the black object throughout the day with exposure to light transmitted through various embodiments of a heat blocking transparent composite described herein.

[28] FIG. 7 shows the temperature of the black object throughout the day with exposure to light transmitted through various embodiments of a heat blocking transparent composite described herein.

[29] FIG. 8 shows the light transmittance versus wavelength spectra for various embodiments of a heat blocking transparent composite described herein.

[30] FIG.9 shows the light transmittance versus wavelength spectra for

HOE/WLC heat blocking film from 90° (normal viewing light) incident angle and 50° (sun light angle) incident angle, respectively.

DETAILED DESCRIPTION

[31 ] The present disclosure generally relates to highly transparent films or composites comprising holographic optical elements which are useful for reducing solar heating. The disclosure describes an approach that employs holographic optical elements to diffract incident light at an angle that will allow the light to reflect out the top or edge surfaces of the film, thus blocking the solar radiation from passing through the film, and reducing the solar heating. In particular, the embodiments described herein are useful for windows in vehicles or buildings. For window-based systems, the currently available products which reduce solar heating inside vehicles or buildings typically utilize a metal oxide reflective film, or tinted (darkened) films, which are not ideal because of the reduction in visual transparency (typically less than 70% transmission of visible wavelengths). The currently disclosed embodiments and methods uses holographic optical elements to diffract the incoming solar radiation at an angle where it is reflected back out of the front or edge surfaces, thus reducing the solar heating while maintaining a clear transparent window (>70% transmittance of visible wavelengths).

[32] For the purposes of this disclosure, the term "transparent" may be applied to any structure through which an object may be visually recognized, including any structure which is sufficiently transparent to be suitable as a window.

[33] A holographic optical element (HOE) is a hologram having a diffraction pattern rendered as a surface relief, or a thin film containing an index modulation throughout the thickness of the film. HOEs are typically produced on a glass plate coated with a film of dichromated gelatin emulsion by exposing it to two mutually coherent laser beams, referred to as object and reference beams. HOEs have been employed to act as concentrators of incoming solar radiation. U.S. Patent No. 5,517,339 discloses a method of manufacturing HOEs. U.S. Patent Nos. 5,877,874, 6,274,860, and 6,469,241 disclose holographic concentrator devices used to separate and concentrate optical radiation. U.S. Patent Application No. 61/903,317 to Nitto Denko Inc. discloses solar energy collection systems utilizing holographic optical elements useful for building integrated photovoltaics. All of the foregoing citations are hereby incorporated by reference in their entireties.

[34] In some embodiments of the current invention, a holographic optical element comprises diffractive elements having varying indices of refraction. When confronted by light of certain angles, the varying indices of refraction of the diffractive elements produce a diffraction pattern that directs the light so that it is reflected out of the edge or top surface (or outside surface with respect to a building or vehicle) of the transparent waveguide substrate.

[35] In some embodiments, the heat blocking transparent composite comprises a holographic optical element and a transparent waveguide substrate. In some embodiments, the holographic optical element and the transparent waveguide substrate of the heat blocking transparent composite are transparent such that they provide little to no visibility distortion making the composite highly useful for window- based building or vehicle applications. In some embodiments, the transparent waveguide substrate comprises a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface. In some embodiments, the at least one holographic optical element is disposed on a surface of the transparent waveguide substrate, wherein the holographic optical element is configured to diffract a portion of incident light to an angle that allows reflection of the light out the edge or top surfaces of the heat blocking transparent composite. In some embodiments, the heat blocking transparent composite is transparent in at least one viewing angle.

[36] In some embodiments, the heat blocking transparent composite is a window. In some embodiments, the window is glass and/or polymer. In some embodiments, the heat blocking transparent composite comprises a pane and a holographic optical element. In some embodiments, the composite is a transparent waveguide substrate. In some embodiments, the composite comprises a holographic optical elements and a transparent waveguide substrate. In some embodiments, the heat blocking transparent composite is a heat blocking transparent film. In some embodiments, the composite is a film.

[37] In some embodiments, the diffractive structures are the same across the length of the holographic optical element. In some embodiments, the diffractive structures continuously vary across the length of the holographic optical element. In some embodiments, the holographic optical element is configured with multiple diffractive structures. In some embodiments, the diffractive structures of the holographic optical element vary throughout the length of the holographic optical element, such that light incident on one side of the holographic optical element is diffracted into the transparent waveguide substrate at a different angle than the light incident on a different side of the holographic optical element. In some embodiments, the diffractive structures of the holographic optical element are continuously varying throughout the length of the holographic optical element. The direction of diffraction for any given angle with respect to the holographic optical element may be controlled based upon the angular position of the two coherent laser beams used to record a hologram of the holographic optical element.

[38] The heat blocking transparent composite may be configured to be transparent at a variety of viewing angles depending on the application and/or location of the window in the building or vehicle, and/or the longitudinal location of the building. In some embodiments of the heat blocking transparent composite, the composite is transparent for a viewing angle of 0 degrees (i.e., the composite is transparent when looking straight through the window as illustrated in FIG. 1 ). In some embodiments, the heat blocking transparent composite may be placed vertically, such as a window in a building. In some embodiments wherein the heat blocking transparent composite is placed vertically, the composite is transparent for a viewing angle of about +20 degrees to about -20 degrees; about +40 degrees to about -40 degrees; about +60 degrees to about -60 degrees; or about +90 degrees to about -90 degrees from horizontal, or from normal to the major top surface of the transparent waveguide substrate. In some embodiments, the heat blocking transparent composite may be placed horizontally, such as a sky light in a building or vehicle.

[39] In some embodiments wherein the heat blocking transparent composite is placed horizontally, the composite is transparent for a viewing angle of about +20 degrees to about -20 degrees; about +40 degrees to about -40 degrees; about +60 degrees to about -60 degrees; or about +90 degrees to about -90 degrees from vertical, or from normal to the major top surface of the transparent waveguide substrate. In some embodiments, the heat blocking transparent composite may be placed at an angle other than horizontal or vertical, in which case, the composite may be designed to be transparent for a viewing angle depending on the particular application.

[40] Solar radiation is directly incident on building windows (which are vertical) at an angle equal to or greater than 0 degrees from vertical. Therefore, in some embodiments it may only be necessary to configure the holographic optical element to diffract light that is incident on the window at angles greater than 0 degrees from vertical, in order to provide adequate heat shielding. In some embodiments of the heat blocking transparent composite, the composite is transparent for a viewing angle of about +20 degrees to about -90 degrees; about +40 degrees to about -90 degrees; about +50 degrees to about -90 degrees; or about +75 degrees to about -90 degrees from horizontal, or from normal to the major top surface of the transparent waveguide substrate.

[41 ] In order for the heat blocking transparent composite to be applicable to window based applications, the composite may be transparent, in at least one viewing angle, to provide undistorted viewing of the scenery through the window. The transmittance of visible light (wavelengths of light between 400 nm and 700 nm) through the composite is a good indicator of transparency. In some embodiments of the heat blocking transparent composite, the composite has a transmittance of at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, and/or at least 90% for wavelengths of light between about 400 nm and 700 nm, for the desired viewing angle of the application (e.g., a 0 degree viewing angle so that an observer may view straight through the window). In some embodiments of the heat blocking transparent composite, the composite has a transmittance in at least one viewing angle of at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, and/or at least 90% for wavelengths of light between 400 nm and 700 nm.

[42] In some embodiments, the holographic optical element is configured to diffract photons into the transparent waveguide substrate at a different angle depending on the incident wavelength. It may be desirable to configure the holographic optical element of the heat blocking transparent composite to diffract portions of the light spectrum at different angles. For instance, for applications which require a high degree of visibility at all angles, such as vehicle windows, the holographic optical element may be configured to allow all visible light to be transmitted through at all angles, while diffracting all angles of incident UV and IR wavelengths. For other applications, such as building windows, the viewing angle required from the inside may be very small, such as +/- 30 degrees from horizontal, or from normal to the major top surface of the transparent waveguide substrate, in which case the holographic optical element may be configured to diffract all angles of incoming UV and IR light, and it may also be configured to diffract visible light with incoming angles greater than +30 degrees or less than -30 degrees from vertical, or from normal to the major top surface of the transparent waveguide substrate. In this manner, the amount of heat that is blocked is maximized, while also maintaining the visibility requirements for the particular application. In some embodiments, the holographic optical element may be optimized to diffract or not diffract different portions of the light spectrum at different angles depending on the application of the heat blocking transparent composite.

[43] In some embodiments, the holographic optical element is configured to diffract all incident UV wavelengths at an angle that allows reflection of the UV wavelengths out the edge or top surfaces of the heat blocking transparent composite. In some embodiments, the holographic optical element is configured to diffract all incident IR wavelengths at an angle that allows reflection of the IR wavelengths out the edge or top surfaces of the heat blocking transparent composite. In some embodiments, the holographic optical element is configured to diffract only incident visible wavelengths of greater than 80 degrees, greater than 60 degrees, greater than 30 degrees, greater than 5 degrees, greater than 80 degrees or less than -80 degrees, greater than 60 degrees or less than -60 degrees, greater than 30 degrees or less than -30 degrees, or greater than 5 degrees or less than -5 degrees (from horizontal, or from normal to the major top surface of the transparent waveguide substrate) at an angle that allows reflection of the visible wavelengths out the edge or top surfaces of the heat blocking transparent composite. In some embodiments of the heat blocking transparent composite, the holographic optical element is made of at least one material selected from the group consisting of dichromated gelatin, photopolymer, bleached and unbleached photo emulsion, nanoparticle doped photopolymer, or any combination thereof.

[44] In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises transparent glass or polymer materials with a refractive index of between about 1 .4 and about 1 .7.

[45] In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises one or multiple transparent layers.

[46] In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises at least one layer formed from polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane, polyacrylate, or combinations thereof. In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises at least one layer made of one host polymer, a host polymer and a co-polymer, multiple polymers, and/or combinations thereof. In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises at least one layer of a transparent inorganic amorphous glass. In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises at least one layer of a glass material selected from the group consisting of silicon dioxide, albite, crown, flint, low iron glass, Borofloat®, borosilicate glass, soda-lime glass, and/or any combination thereof.

[47] In some embodiments, a luminescent material is incorporated into the heat blocking transparent composite to further enhance the solar heat blocking effect. In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range, and re-emit those photons at a different wavelength, wherein a portion of the re-emitted photons are internally reflected and refracted within the transparent waveguide substrate until they reach the edges of the substrate where they exit the composite. In some embodiments, the luminescent material absorbs UV photons and converts these photons into visible wavelengths.

[48] In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range, and re-emit those photons at a different wavelength, wherein the re-emitted photons are internally reflected and refracted within the transparent waveguide substrate until they reach the edge or top surfaces where they can escape back into the environment. In some embodiments, the transparent waveguide substrate comprises a single wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and at least one luminescent material. In some embodiments, the transparent waveguide substrate comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and a luminescent material. In some embodiments, the wavelength conversion layer or layers may be in between glass or polymer plates, wherein the glass or polymer plates also act to internally reflect and refract photons towards the edge surface. In some embodiments, the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also acts to internally reflect and refract photons towards the edge surface.

[49] The heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, as described herein, may include additional layers. For example, the system may comprise an adhesive layer in between the holographic optical element and transparent waveguide substrate. In some embodiments the system may also comprise additional glass or polymer layers. In some embodiments, the additional glass or polymer layers may be incorporated into the transparent waveguide substrate to include a wavelength conversion layer in between the glass or polymer layers and to protect it from environmental elements. In some embodiments, the additional glass or polymer layers may be used which encapsulate the holographic optical elements or may be placed on top of the wavelength conversion layer. The glass or polymer layers may be configured to protect and prevent oxygen and moisture penetration into the wavelength conversion layer. In some embodiments, the glass or polymer layers may be used to internally refract or reflect photons that are emitted from the holographic optical element. In some embodiments, the system may further comprise a polymer layer comprising a UV absorber, configured to prevent harmful high energy photons from transmitting through the window into the building and/or contacting the wavelength conversion layer. In some embodiments, it may also be possible to combine layers to optimize different advantages together into one device.

[50] The diffractive structures employed in a holographic optical element act to diffract the incident light into the transparent waveguide substrate. The diffractive structures for each heat blocking transparent composite must be optimized for the particular system, with regards to the size, shape of the system, and its location on the building and latitude. In some embodiments of the heat blocking transparent composite, the diffractive structures of the holographic optical element are different throughout the length of the holographic optical element. In some embodiments, the multiple diffractive structures of the holographic optical element are configured to diffract a portion of the solar radiation at a different angle into the transparent waveguide substrate depending on the angle of incidence of the light onto the holographic optical element. In other embodiments, the multiple diffractive structures of the holographic optical element are configured to maximize the loss of photons reflected out of the transparent waveguide substrate so that the heat transmitted through the window is minimized. In some embodiments, the holographic optical element may cover the entire light-incident surface of the transparent waveguide substrate. In some embodiments, the holographic optical element may only cover a portion of the entire light-incident surface of the transparent waveguide substrate.

[51 ] In some embodiments of the heat blocking transparent composite, the holographic optical element is configured to diffract photons into the transparent waveguide substrate at a different angle depending on the incident wavelength. For example, the holographic optical element may diffract UV and IR light at an angle that will allow reflection of the light out the edges or top of the transparent waveguide substrate, while at the same time, the holographic optical element may allow visible wavelengths to transmit through the window to the inside of the building.

[52] The holographic optical element may be made of various materials using methods known in the art. In some embodiments of the heat blocking transparent composite, the holographic optical element comprises one or a multiplicity of materials. In some embodiments of the heat blocking transparent composite, the holographic optical element is made of at least one material selected from the group consisting of dichromated gelatin, photopolymer, bleached or unbleached photo emulsion, and/or any combination thereof.

[53] Numerous methods may be used to manufacture HOEs. Such methods have been described in the art, such as U.S. Patent Nos. 5,517,339; 5,877,874; 6,274,860; and 6,469,241 , and U.S. Patent Publication No. 2010/0186818, which are hereby incorporated by reference in their entireties.

[54] The holographic optical element is written into dichromated gelatin

(DCG) which is fabricated using standard techniques know in the art (see B.J. Chang and CD. Leonard, Dichromated gelatin for the fabrication of holographic optical elements, Applied Optics, Vol. 18, Issue 14, pp. 2407 (1979), or http://holoinfo.no- ip.biz/wiki/index.php/Dichromated_Gelatin), which is hereby incorporated by reference in its entirety. In some embodiments, in-house deposition of DCG layers is performed to increase Δη to improve HOE efficient performance in IR.

[55] The transparent matrix of the transparent waveguide substrate may comprise a material selected from a glass and a transparent polymer, or any material that is transparent and is compatible with the heat blocking transparent composite. In some embodiments, the transparent matrix of the transparent waveguide substrate may need to be transparent to IR, UV, and/or visible light in various combinations. In some embodiments, the transparent matrix of the transparent waveguide substrate is transparent over a large section of the visible spectrum. For example, a suitable transparent polymer would be poly(methyl methacrylate) polymer (PMMA, which typically has a refractive index of about 1 .49) or a polycarbonate polymer (typical refractive index of about 1 .58). The glass may be selected from any known transparent inorganic amorphous material, including, but not limited to, glasses comprising silicon dioxide and glasses selected from the albite type, crown type and flint type. These glasses have refractive indexes ranging from approximately 1 .45 to 1 .9. In some embodiments of the heat blocking transparent composite, at least one layer of the transparent waveguide substrate comprises transparent glass or polymer materials with a refractive index of between about 1 .4 and about 1 .7.

[56] In some embodiments of the heat blocking transparent composite, the holographic optical element is incorporated into the transparent waveguide substrate. In some embodiments, the transparent waveguide substrate comprises an optically transparent polymer layer in between two glass plates, wherein the holographic optical element is incorporated into the optically transparent polymer layer. In some embodiments, the optically transparent polymer layer comprises an epoxy.

[57] It is also possible to further enhance the heat blocking transparent composite by employing luminescent materials. Therefore, in some embodiments of the heat blocking transparent composite, the composite further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range, and re-emit those photons at a different wavelength. The re-emitted photons may be internally reflected and refracted within the transparent waveguide substrate until they reach the edges where they exit the composite. The application of a holographic optical element in conjunction with a transparent waveguide substrate comprising a luminescent material may enhance the solar heat blocking of the composite. In some embodiments, the holographic optical element is configured to diffract the UV and visible portions of the solar spectrum into the transparent waveguide substrate at an angle that prevents the photons from transmitting through the window into the inside environment, and preventing solar heating. In some embodiments, the transparent waveguide substrate comprises at least one wavelength conversion layer. In some embodiments, the wavelength conversion layer is configured to convert photons of a particular wavelength to a more desirable wavelength that is more efficiently reflected or blocked by the heat blocking transparent composite.

[58] In some embodiments, the heat blocking transparent composite comprises a single wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and at least one luminescent material. In some embodiments, the heat blocking transparent composite comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and a luminescent material. In some embodiments, the wavelength conversion layer or layers may be in between glass or polymer plates, wherein the glass or polymer plates also act to internally reflect and refract photons towards the edge surface. In some embodiments, the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also act to internally reflect and refract photons towards the edge surface.

[59] The luminescent material may be dispersed inside the transparent matrix of the transparent waveguide substrate, deposited on at least one side of the transparent waveguide substrate, or in between two separate transparent layers. In some embodiments, the transparent waveguide substrate comprises a single layer, wherein said layer is a wavelength conversion layer and the wavelength conversion layer comprises a polymer matrix and at least one luminescent material. In some embodiments, the transparent waveguide substrate comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer and the wavelength conversion layer comprises a polymer matrix and a luminescent material. In some embodiments, the wavelength conversion layer or layers may be in between glass or polymer plates, wherein the glass or polymer plates also act to internally reflect and refract photons towards the edge surface. In some embodiments, the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also act to internally reflect and refract photons towards the edge surface.

[60] In some embodiments of the heat blocking transparent composite, the holographic optical element is incorporated into the transparent waveguide substrate. In some embodiments, the transparent waveguide substrate comprises a wavelength conversion layer in between two glass plates, wherein the holographic optical element is incorporated into the wavelength conversion layer, and wherein the wavelength conversion layer comprises a luminescent material and a polymer matrix. In some embodiments, the polymer matrix of the wavelength conversion layer comprises an epoxy.

[61 ] In order for the heat blocking transparent composite to be used in window based applications, the polymer matrix of the wavelength conversion layer should be sufficiently transparent to allow visibility. In some embodiments of the heat blocking transparent composite, the polymer matrix of the wavelength conversion layer is formed from polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane, polyacrylate, polyepoxide, or combinations thereof. In some embodiments of the heat blocking transparent composite, the polymer matrix may be made of one host polymer or a host polymer and a co-polymer. In some embodiments of the composite, the polymer matrix may be made of multiple polymers.

[62] Preferably, the polymer matrix material used in the wavelength conversion layer has a refractive index in the range of about 1 .4 to about 1 .7. In some embodiments, the refractive index of the polymer matrix material used in the wavelength conversion layer is in the range of about 1 .45 to about 1 .55.

[63] A luminescent material, sometimes referred to as a chromophore or fluorescent dye, is a compound that absorbs photons of a particular wavelength or wavelength range, and re-emits the photon at a different wavelength or wavelength range. Chromophores used in film media can greatly enhance the performance of solar cells and photovoltaic devices. However, such devices are often exposed to extreme environmental conditions for long periods of time, e.g., 20 or more years. As such, maintaining the stability of the chromophore over a long period of time is important. In some embodiments, chromophore compounds with good photostability for long periods of time, e.g., 20,000 or more hours of illumination under one sun (AM1 .5G) irradiation with <10% degradation, are preferably used in the film comprising a holographic optical element, a transparent waveguide concentrator, and wavelength conversion layer.

[64] Luminescent materials can be up-converting or down-converting. In some embodiments, the at least one luminescent material may be an up-conversion luminescent material, meaning a compound that converts photons from lower energy (long wavelengths) to higher energy (short wavelengths). Up-conversion dyes may include rare earth materials which have been found to absorb photons of wavelengths in the infrared (IR) region, about 975 nm, and re-emit in the visible region (about 400-700 nm), for example, Yb³⁺, Tm³⁺, Er³⁺, Ho³⁺, and NaYF⁴. Additional up-conversion materials are described in U.S. Patent Nos. 6,654,161 and 6,139,210, and in the Indian Journal of Pure and Applied Physics, volume 33, pages 169-178, (1995), which are hereby incorporated by reference in their entireties. In some embodiments, the at least one luminescent material may be a down-shifting luminescent material, meaning a compound that converts photons of high energy (short wavelengths) into lower energy (long wavelengths). In some embodiments, the down-shifting luminescent material may be a derivative of perylene, benzotriazole, or benzothiadiazole, as are described in U.S. Provisional Patent Application Nos. 61 /430,053; 61 /485,093; and 61 /539,392, which are hereby incorporated by reference in their entireties. In some embodiments, the wavelength conversion layer comprises both an up-conversion luminescent compound and a down-shifting luminescent compound.

[65] In some embodiments, the luminescent material is configured to convert incoming photons of a first wavelength to a different second wavelength. In some embodiments, the luminescent material is a down-shifting material. Various luminescent materials may be used. In some embodiments of the heat blocking transparent composite, at least one of the luminescent materials is a quantum dot material. In some embodiments, the at least one luminescent material is an organic dye. In some embodiments, the at least one luminescent material is selected from perylene derivative dyes, benzotriazole derivative dyes, diazaborinine derivative dyes, benzothiadiazole-derivative dyes and/or combinations thereof.

[66] In some embodiments, the at least one chromophore is an organic compound. In some embodiments, the at least one chromophore is selected from perylene derivative dyes, benzotriazole derivative dyes, benzothiadiazole derivative dyes, and/or combinations thereof. Examples of chromophores may be found in U.S. Patent Publication US2013/0074927, which is hereby incorporated by reference in its entirety.

[67] It is important that the heat blocking transparent composite remain sufficiently transparent for use in building and vehicle window based applications. Luminescent materials in the UV wavelength spectrum are typically clear, and would not alter the color if used in the wavelength conversion film. In some embodiments, the heat blocking transparent composite comprises a luminescent material that shifts wavelengths in the UV portion of the spectrum into the visible or IR portions of the spectrum and directs the light through reflection to the edges of the transparent waveguide substrate. In some embodiments, the luminescent material is optimized to be highly absorbing in the UV and transparent in the visible portion of the solar spectrum. The luminescent material efficiency is independent of angle of incidence, allowing operation over a broad range of incidence angles.

[68] In some embodiments, the luminescent material comprises an organic photostable chromophore. In some embodiments, the at least one luminescent material comprises a structure as given by the following general formula (I):

wherein R-i , R₂, and R3 comprise and alkyl, a substituted alkyl, or an aryl. Example

[69] The term "alkyl" refers to a branched or straight fully saturated acyclic aliphatic hydrocarbon group (i.e., composed of carbon and hydrogen containing no double or triple bonds). Alkyls include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, and the like.

[70] The term "heteroalkyl" used herein refers to an alkyl group comprising one or more heteroatoms. When two or more heteroatoms are present, they may be the same or different.

[71 ] The term "cycloalkyl" used herein refers to saturated aliphatic ring system radical having three to twenty-five carbon atoms including, but not limited to, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.

[72] The term "polycycloalkyl" used herein refers to saturated aliphatic ring system radical having multiple cylcoalkyl ring systems.

[73] The term "alkenyl" used herein refers to a monovalent straight or branched chain radical of from two to twenty-five carbon atoms containing at least one carbon double bond including, but not limited to, 1 -propenyl, 2-propenyl, 2- methyl-1 -propenyl, 1 -butenyl, 2-butenyl, and the like.

[74] The term "alkynyl" used herein refers to a monovalent straight or branched chain radical of from two to twenty-five carbon atoms containing a carbon triple bond including, but not limited to, 1 -propynyl, 1 -butynyl, 2-butynyl, and the like.

[75] The term "aryl" used herein refers to homocyclic aromatic radical whether one ring or multiple fused rings. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, phenanthrenyl, naphthacenyl, fluorenyl, pyrenyl, and the like. Further examples include:

naphthalen-1-yl naphthalen-2-yl anthracen-1 -yl anthracen-2-yl anthracen-9-yl

pyren-1-yl perylen-3-yl 9H-fluoren-2-yl

[76] The term "alkaryl" or "alkylaryl" used herein refers to an alkyl- substituted aryl radical. Examples of alkaryl include, but are not limited to, ethylphenyl, 9,9-dihexyl-9H-fluorene, and the like.

[77] The term "aralkyl" or "arylalkyl" used herein refers to an aryl-substituted alkyl radical. Examples of aralkyl include, but are not limited to, phenylpropyl, phenylethyl, and the like. [78] The term "heteroaryl" used herein refers to an aromatic group comprising one or more heteroatoms, whether one ring or multiple fused rings. When two or more heteroatoms are present, they may be the same or different. In fused ring systems, the one or more heteroatoms may be present in only one of the rings. Examples of heteroaryl groups include, but are not limited to, benzothiazyl, benzoxazyl, quinazolinyl, quinolinyl, isoquinolinyl, quinoxalinyl, pyridinyl, pyrrolyl, oxazolyl, indolyl, thiazyl, and the like. Further examples of substituted and unsubstituted heteroaryl rings include:

pyridin-2-yl pyridin-4-yl 2-cyanopyridin-5-yl pyridazin-3-yl pyridazin-4-yl

pyrimidin-2-yl pyrimidin-4-yl pyrazin-2-yl triazin-2-yl

uinolin-2-yl quinolin-4-yl quinolin-6-yl ^υίηοϋη-Ί -Υ¹ quinazolin-2-yl

quinazolin-4-yl phthalazin-1 -yl quinoxalin-2-yl naphthyridin-4-yl 9H-purin-6-yl

benzofuran-2-yl benzothiophen-2-yl 9H-carbazol-2yl dibenzofuran-4-yl dibenzothiophen-4-yl

[79] The term "alkoxy" used herein refers to straight or branched chain alkyl radical covalently bonded to the parent molecule through an -O- linkage. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, n-butoxy, sec-butoxy, t-butoxy, and the like.

[80] The term "heteroatom" used herein refers to any atom that is not C

(carbon) or H (hydrogen). Examples of heteroatoms include S (sulfur), N (nitrogen), and O (oxygen).

[81 ] The term "cyclic amino" used herein refers to either secondary or tertiary amines in a cyclic moiety. Examples of cyclic amino groups include, but are not limited to, aziridinyl, piperidinyl, N-methylpiperidinyl, and the like.

[82] The term "cyclic imido" used herein refers to an imide in the radical of which the two carbonyl carbons are connected by a carbon chain. Examples of cyclic imide groups include, but are not limited to, 1 ,8-naphthalimide, pyrrolidine-2,5- dione, 1 H-pyrrole-2,5-dione, and the like.

[83] The term "alcohol" used herein refers to a radical -OH.

[84] The term "acyl" used herein refers to a radical -C(=0)R.

[85] The term "aryloxy" used herein refers to an aryl radical covalently bonded to the parent molecule through an -O- linkage.

[86] The term "acyloxy" used herein refers to a radical -0-C(=0)R.

[87] The term "carbamoyl" used herein refers to a radical -C(=0)NH₂. [88] The term "carbonyl" used herein refers to a functional group C=0.

[89] The term "carboxy" used herein refers to a radical -COOR.

[90] The term "ester" used herein refers to a functional group RC(=0)OR'.

[91] The term "amido" used herein refers to a radical -C(=0)NR'R".

[92] The term "amino" used herein refers to a radical -NR'R".

[93] The term "heteroamino" used herein refers to a radical -NR'R" wherein

R' and/or R" comprises a heteroatom.

[94] The term "heterocyclic amino" used herein refers to either secondary or tertiary amines in a cyclic moiety wherein the group further comprises a heteroatom.

[95] The term "cycloamido" used herein refers to an amido radical of -

C(=0)NR'R" wherein R' and R" are connected by a carbon chain.

[96] The term "sulfone" used herein refers to a sulfonyl radical of -S(=0)2R.

[97] The term "sulfonamide" used herein refers to a sulfonyl group connected to an amine group, the radical of which is -S(=0)2-NR'R".

[98] As used herein, a substituted group is derived from the unsubstituted parent structure in which there has been an exchange of one or more hydrogen atoms for another atom or group. When substituted, the substituent group(s) is (are) one or more group(s) individually and independently selected from C1-C25 alkyl, C₂- C25 alkenyl, C2-C25 alkynyl, C3-C25 cycloalkyl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, alcohol, carboxyl, haloalkyl, CN , OH, -S0₂-alkyl, -CF₃, and -OCF3); cycloalkyl geminally attached, C1-C25 heteroalkyl, C3-C25 heterocycloalkyl (e.g., tetrahydrofuryl) (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, alcohol, carboxyl, CN , -S0₂-alkyl, -CF₃, and -OCF₃); aryl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, arylalkyl, alkoxy, alcohol, aryloxy, carboxyl, amino, imido, amido (carbamoyl), optionally substituted cyclic imido, cylic amido, CN, -NH-C(=0)-alkyl, -CF₃,-OCF₃, and aryl optionally substituted with C C25 alkyl); arylalkyl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, alcohol, aryl, carboxyl, CN, -S0₂-alkyl, -CF₃, and - OCF₃); heteroaryl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, alcohol, aryl, heteroaryl, aralkyl, carboxyl, CN, -S0₂- alkyl, -CF₃, and -OCF₃); halo (e.g., chloro, bromo, iodo and fluoro), cyano, hydroxy, optionally substituted cyclic imido, amino, imido, amido, -CF₃, C1-C25 alkoxy (optionally substituted with halo, alkyl, alkoxy, aryl, carboxyl, CN, OH, -S0₂-alkyl, - CF₃, and -OCF₃); aryloxy, acyloxy, sulfhydryl (mercapto); halo(CrC₆)alkyl, Ci-C₆ alkylthio, arylthio, mono- and di-(CrC6)alkyl amino; quaternary ammonium salts, amino(Ci-C₆)alkoxy, hydroxy(Ci-C₆)alkylamino, amino(Ci-C₆)alkylthio, cyanoamino, nitro, carbamoyl, keto (oxy), carbonyl, carboxy, acyl, glycolyl, glycyl, hydrazino, guanyl, sulfamyl, sulfonyl, sulfinyl, thiocarbonyl, thiocarboxy, sulfonamide, ester, C- amide, N-amide, N-carbamate, O-carbamate, urea, and combinations thereof. Wherever a substituent is described as "optionally substituted" that substituent may be substituted with the above substituents.

[99] In some embodiments, the first chromophore comprises a structure as given by the following formula (ll-a) or (ll-b):

wherein R³ is selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted heteroalkyi, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R³ is an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyl, aryl, heterocycloalkyl, or heteroaryl; R⁴, R⁵, and R⁶ are independently selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted heteroalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R⁴ and R⁵, R⁴ and R⁶, R⁵ and R⁶, or R⁴ and R⁵ and R⁶, together from an optionally substituted ring or an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyl, aryl, heterocyclalkyl, or heteroaryl; and L is selected from the group consisting of optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted alkynylene, optionally substituted arylene, and optionally substituted heteroarylene.

[100] In some embodiments, R³ in formula ll-a and formula ll-b is selected from the group consisting of C-i-25 alkyl, C-i-25 heteroalkyl, C2-25 alkenyl, C3-25 cycloalkyl, polycycloalkyl, heterocycloalkyl, arylalkyl; and R³ may be optionally substituted with one or more of any of the following substituents: C-i-25 alkyl, C-i-25 heteroalkyl, C₂-25 alkenyl, C3-25 cycloalkyl, polycycloalkyl, heterocycloalkyl, aryl, heteroaryl, OH, C_mH₂m+iO ether, C_mH₂m+iCO ketone, C_mH₂m+iC0₂ carboxylic ester, C_mH₂m+iOCO carboxylic ester, ArO aryloxy, ArCO aryl ketone, ArC0₂ ester of aryl- carboxylic acid, ArOCO carboxylic ester of phenol, (CmH2m+i)(CpH_{2 +}i)N amine, c- (CH₂)_SN amine, (C_mH₂m₊i)(CpH₂p₊i)NCO amide, c-(CH₂)_sNCO amide, C_mH₂m₊iCON(CpH₂p₊i) amide, CN, C_mH_2m+iS0₂ sulfone, (C_mH₂m₊i)(CpH₂p₊i)NS02 sulfonamide, CmH2m+iS02N(CpH₂p+i) sulfonamide, or c-(CH₂)_sNS02 sulfonamide, wherein m is an integer in the range of 1 to 20, p is an integer in the range of 1 to 20, s is an integer in the range of 2 to 6, and Ar is any aromatic or heteroaromatic ring. R⁴, R⁵, and R⁶ in formula ll-a and formula ll-b are independently selected from the group consisting of C-1-25 alkyl, C1-25 heteroalkyl, C2-25 alkenyl, C3-25 cycloalkyl, polycycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, C0₂CmH2m+i carboxyhc ester, (CmH2m+i )(CpH_{2 +}i)NCO amide, c-(CH₂)_sNCO amide, COC_mH₂m+i ketone, COAr, S02C_mH₂m+i sulfone, S0₂Ar sulfone, (C_mH2m+i )(CpH₂p₊i)S02 sulfonamide, c-(CH₂)_sS0₂ sulfonamide; and R⁴, R⁵, and R⁶ are independently optionally substituted with one or more of any of the following substituents: C-i-25 alkyl, C-i-25 heteroalkyl, C2-25 alkenyl, C3-25 cycloalkyl, polycycloalkyl, heterocycloalkyl, aryl, heteroaryl, OH, C_mH₂m+i O ether, C_mH₂m+i CO ketone, C_mH₂m+iC02 carboxyhc ester, C_mH₂m+iOCO carboxyhc ester, ArO aryloxy, ArCO aryl ketone, ArC0₂ ester of aryl carboxyhc acid, ArOCO carboxyhc ester of phenol, (C_mH₂m₊i )(CpH₂p₊i)N amine, c-(CH₂)_sN amine, (C_mH₂m₊i )(CpH₂p₊i)NCO amide, c-(CH₂)_sNCO amide, C_mH2m+iCON(CpH₂p₊i ) amide, C_mH₂m+iS02 sulfone, (C_mH2m+i )(CpH₂p₊i)NS02 sulfonamide, C_mH2m+iS02N(CpH₂p₊i ) sulfonamide, or c- (CH₂)_SNS0₂ sulfonamide, wherein m is an integer in the range of 1 to 20, p is an integer in the range of 1 to 20, s is an integer in the range of 2 to 6, and Ar is any aromatic or heteroaromatic ring. L in formula ll-b is selected from the group consisting of C-i-25 alkyl, C-i-25 heteroalkyl, C₂-25 alkenyl; and L may be optionally substituted with one or more of any of the following substituents: C-i-25 alkyl, C-i-25 heteroalkyl, C₂-25 alkenyl, C3-25 cycloalkyl, polycycloalkyl, heterocycloalkyl, aryl, heteroaryl, OH, C_mH₂m+i O ether, C_mH₂m+i CO ketone, C_mH₂m+iC0₂ carboxyhc ester, C_mH₂m+iOCO carboxyhc ester, ArO aryloxy, ArCO aryl ketone, ArC0₂ ester of aryl- carboxylic acid, ArOCO carboxyhc ester of phenol, (C_mH2m+i )(CpH₂p₊i)N amine, c- (CH₂)sN amine, (CmH₂m₊i )(CpH₂p₊i)NCO amide, c-(CH₂)_sNCO amide, C_mH₂m₊iCON(CpH₂p₊i ) amide, CN, C_mH_2m+iS0₂ sulfone, (C_mH₂m₊i )(CpH₂p₊i)NS02 sulfonamide, C_mH2m+iS02N(CpH₂p₊i ) sulfonamide, or c-(CH₂)_sNS0₂ sulfonamide, wherein m is an integer in the range of 1 to 20, p is an integer in the range of 1 to 20, s is an integer in the range of 2 to 6, and Ar is any aromatic or heteroaromatic ring.

[101 ] In some embodiments, R³ in formula ll-a and formula ll-b is selected from the group consisting of C-i-25 alkyl, C-i-25 heteroalkyl, C2-25 alkenyl, C3-25 cycloalkyl, C5-25 polycycloalkyl, C-i-25 heterocycloalkyl, C-i-25 arylalkyl; R⁴, R⁵, and R⁶ are independently optionally substituted with one or more of any of the following substituents: C-1-25 alkyl, C1-25 heteroalkyl, C2-25 alkenyl, C3-25 cycloalkyl, C1-25 aryl, and C-1-25 heteroaryl.

[102] In he first chromophore is selected from the group consisting

[103] Preferably, the at least one luminescent material is present in the polymer matrix of the wavelength conversion layer in an amount in the range of about 0.01 wt% to about 10 wt%; about 0.01 wt% to about 3 wt%; about 0.05 wt% to about 2 wt%; or about 0.1 wt% to about 1 wt%, by weight of the polymer matrix, or any weight bounded by or between any of these ranges.

[104] In some embodiments, the thickness of the wavelength conversion layer is in the range of about 10 μιη to about 2 mm or about 50 μιη to about 1 mm or any thickness bounded by or between any of these ranges.

[105] In some embodiments, the heat blocking transparent composite may have a thickness in the range of about 100 μιη to about 30 mm; from about 0.5 mm to about 1 mm; from about 1 mm to about 2 mm; from about 2 mm to about 3 mm; from about 3 mm to about 4 mm; from about 4 mm to about 5 mm; from about 5 mm to about 6 mm; from about 6 mm to about 7 mm; from about 7 mm to about 8 mm; from about 8 mm to about 9 mm; from about 9 mm to about 10 mm; from about 10 mm to about 1 1 mm; from about 1 1 mm to about 12 mm; from about 12 mm to about 13 mm; from about 13 mm to about 14 mm; from about 14 mm to about 15 mm; from about 15 mm to about 16 mm; from about 16 mm to about 17 mm; from about 17 mm to about 18 mm; from about 18 mm to about 19 mm; from about 19 mm to about 20 mm; from about 20 mm to about 22 mm; from about 22 mm to about 24 mm; or any thickness bounded by or between any of these ranges. [106] In some embodiments, the top surface of the transparent waveguide substrate has an area of at least about 100 cm², at least about 200 cm², at least about 300 cm², at least about 400 cm², at least about 500 cm², at least about 600 cm² at least about 700 cm², at least about 800 cm², at least about 900 cm², at least about 1000 cm², and up to 10,000 m² or any area bounded by or between any of these ranges.

[107] In some embodiments, the transparent waveguide substrate may have a thickness in the range of about 1 mm to about 30 mm; from about 3 mm to about 20 mm; from about 5 mm to about 15 mm; from about 8 mm to about 12 mm; from about 2 mm to about 4 mm; from about 3 mm to about 5 mm; from about 5 mm to about 7 mm; from about 7 mm to about 9 mm; or any thickness bounded by or between any of these ranges.

[108] In some embodiments, the wavelength conversion layer comprises more than one luminescent material, for example, at least two different luminescent materials. In some embodiments of the heat blocking transparent composite, the two or more luminescent materials absorb photons in the UV wavelength region. It may be desirable to have multiple luminescent materials in the wavelength conversion layer, depending on the application. In some embodiments, a first chromophore may act to convert photons having wavelengths in the range of about 300 nm to about 350 nm into photons of a wavelength of about 450 nm, and a second chromophore may act to convert photons having wavelengths in the range of about 350 nm to about 400 nm into photons of a wavelength of about 450 nm. Particular wavelength control may be selected based upon the luminescent material(s) utilized.

[109] Various configurations of the luminescent materials in the heat blocking transparent composite are possible. In some embodiments of the heat blocking transparent composite, the transparent waveguide substrate comprises two or more wavelength conversion layers, wherein each of the wavelength conversion layers independently comprises a different luminescent material such that each of the wavelength conversion layers absorbs photons at a different wavelength range. In some embodiments, two or more luminescent materials are mixed together within the same layer, such as, for example, in the wavelength conversion layer. In some embodiments, two or more luminescent materials are located in separate layers or sublayers within the system. For example, the wavelength conversion layer comprises a first luminescent material, and an additional polymer sublayer comprises a second luminescent material.

[110] The holographic optical element may separate the incident light and diffract the separated light at different angles depending on the wavelength of the light. In some embodiments, the holographic optical element is configured to separate the solar spectrum into different wavelengths for multiple incident angles of incoming light. For example, light is incident on the solar module at different angles during the day, where in the morning the light is at a low angle, in the middle of the day the light may be directly above the module, and in the evening the light is again at a low angle. The holographic optical element may have multiple holograms to account for the different angles of incident light, and is therefore able to "passively" track the incident light, and separate the spectrum into different wavelengths. In some embodiments, the holographic optical element is configured to separate potentially harmful UV portions of the solar spectrum from the visible portion of the spectrum, such that the UV wavelengths are refracted out of the system without being transmitted through the window. In some embodiments, the holographic optical element is configured to separate the IR portion of the solar spectrum from the visible portion of the solar spectrum, such that light having IR wavelengths is refracted out of the system without being transmitted through the window.

[111 ] The heat blocking transparent composite may further comprise a photovoltaic or solar cell. The heat blocking transparent composite may be configured for different types of solar energy conversion devices. In some embodiments of the heat blocking transparent composite, the photovoltaic cell is attached to the edge surface of the heat blocking transparent composite and the photovoltaic cell absorbs a portion of the light that is diffracted by the holographic optical element. In some embodiments, the solar energy conversion device is selected from the group consisting of a silicon-based device, a ll l-V or ll-VI PN junction device, a Copper-Indium-Gallium-Selenium (CIGS) thin film device, an organic sensitizer device, an organic thin film device, or a Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) thin film device. In some embodiments, the photovoltaic device or solar cell may be an amorphous Silicon (a-Si) solar cell. In some embodiments, the photovoltaic device or solar cell comprises a microcrystalline Silicon (μο-Si) solar cell. In some embodiments, the photovoltaic device or solar cell may be a crystalline Silicon (c-Si) solar cell.

[112] In some embodiments, the heat blocking transparent composite may not include a photovoltaic or solar cell. In some embodiments the heat blocking transparent composite is not coupled with a solar energy conversion device.

[113] In some embodiments of the heat blocking transparent composite, additional materials may be used, such as glass layers or polymer layers. The materials may be used to protect the holographic element. In some embodiments, glass layers selected from low iron glass, borosilicate glass, or soda-lime glass, may be used in the composite. In some embodiments, the composition of the glass or polymer layers may also further comprise a strong UV absorber to block harmful high energy radiation.

[114] In some embodiments, additional materials or layers may be used such as edge sealing tape, frame materials, polymer materials, or adhesive layers to adhere additional layers to the device. In some embodiments, the device further comprises an additional polymer layer containing a UV absorber. In some embodiments, the substantially transparent waveguide substrate further comprises a UV absorber.

[115] In some embodiments of the heat blocking transparent composite, the composite further comprises a UV stabilizer, antioxidant, absorber, which may act to block high energy irradiation. In some embodiments of the heat blocking transparent composite, the composite further comprises means for binding the holographic optical element, the transparent waveguide substrate, and any additional layer in the composite.

[116] Multiple configurations of the composite are also possible. In some embodiments, the holographic optical element is optically attached to a transparent waveguide substrate, where incoming light hits the holographic optical element, and is diffracted such that light at a certain angle (i.e., greater than +50 degrees from horizontal, or from normal to the major top surface of the transparent waveguide substrate) are reflected directly out of the module, while light that is incident on the window within the desired line of sight (i.e., angles less +30 from horizontal, or from top surface of the transparent waveguide substrate) are allowed to transmit through the window, as illustrated in FIG. 2. In some embodiments, the holographic optical element is optically attached to a transparent waveguide substrate, where incoming light hits the holographic optical element, and is diffracted such that light at certain angles and of undesirable wavelengths are refracted directly out of the module, while the light within the line of sight and of desirable (i.e., visible) wavelengths are allowed to transmit through the window, as illustrated in FIGS. 3-5.

[117] As shown in FIG. 2, the exemplified system comprises a holographic optical element 100 attached to a transparent waveguide substrate 101 , wherein the transparent waveguide substrate comprises a transparent matrix having a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface through which radiation may escape. The holographic optical element 100 is disposed on the transparent waveguide substrate, wherein light is incident on the composite at different angles throughout the day and wherein the holographic optical element is configured to allow incident light 102 through the composite that is within the viewers line of sight 103 so that this view is undistorted. Further, the holographic optical element is configured to diffract incident light 102 on the window at angle outside of the viewer's line of sight at an angle that allows the light to exit the system without being transmitted through the window, thus reducing the heat due to solar radiation inside the building or vehicle.

[118] Another embodiment of the system is shown in FIG. 3, comprising a holographic optical element 100 attached to a transparent waveguide substrate 101 , wherein the transparent waveguide substrate comprises a transparent matrix having a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface through which radiation can escape. The holographic optical element 100 is disposed on the transparent waveguide substrate, wherein light is incident on the composite at different angles throughout the day and wherein the holographic optical element is configured to allow a portion of the desirable incident light (visible) 104 through the composite that is within the viewers line of sight 103 so that this view is undistorted. Further, the holographic optical element is configured to diffract the undesirable incident light (UV) 105 and (IR) 106 at an angle that allows the light to exit the system without being transmitted through the window, thus reducing the heat due to solar radiation inside the building or vehicle.

[119] Another embodiment of the system is shown in FIG. 4, comprising a holographic optical element 100 attached to a transparent waveguide substrate 101 , wherein the transparent waveguide substrate comprises a transparent matrix having a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface through which radiation can escape. The holographic optical element 100 is disposed on the transparent waveguide substrate, wherein light is incident on the composite at different angles throughout the day and wherein the holographic optical element is configured to allow a portion of the desirable incident light (visible) 104 through the composite that is within the viewer's line of sight 103 so that this view is undistorted. Further, the holographic optical element is configured to diffract the undesirable incident light (UV) 105 and (IR) 106 at an angle that allows the light to exit the system without being transmitted through the window, thus reducing the heat due to solar radiation inside the building or vehicle. The composite further comprises a wavelength conversion layer 107 where a portion of the light (UV wavelengths) are absorbed by the luminescent material in the wavelength conversion layer and re-emitted from the wavelength conversion layer at a wavelength in the visible light spectrum, and the transparent waveguide substrate then directs the visible wavelengths to its edges and out of the composite.

[120] Another embodiment of the system is shown in FIG. 5, comprising a holographic optical element 100 attached to a transparent waveguide substrate 101 , wherein the transparent waveguide substrate comprises a transparent matrix having a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface through which radiation can escape. The holographic optical element 100 is disposed on the transparent waveguide substrate, wherein light is incident on the composite at different angles throughout the day and wherein the holographic optical element is configured to allow a portion of the desirable incident light (visible) 104 through the composite that is within the viewers line of sight 103 so that this view is undistorted. Further, the holographic optical element is configured to diffract the undesirable incident light (UV) 105 and (IR) 106 at an angle that allows the light to exit the system without being transmitted through the window, thus reducing the heat due to solar radiation inside the building or vehicle. The composite further comprises a wavelength conversion layer 107 where a portion of the light (UV wavelengths) are absorbed by the luminescent material in the wavelength conversion layer and re-emitted from the wavelength conversion layer at a wavelength in the visible light spectrum, and the transparent waveguide substrate then directs the visible wavelengths to its edges and out of the composite. The composite further comprises a solar energy conversion device 108, which is positioned on the edge of the transparent waveguide substrate so that the diffracted light may be collected and converted into energy by the solar energy conversion device. In some embodiments, the heat blocking transparent composite comprising a holographic optical element, a transparent waveguide substrate, a wavelength conversion layer, and a solar energy conversion device may be optimized to maximize heat blocking ability, visibility, and solar energy harvesting.

[121 ] In some embodiments, the holographic optical element is optically attached to a transparent waveguide substrate, where the transparent waveguide substrate comprises at least one wavelength conversion layer, where incoming light hits the holographic optical element, is separated such that undesirable wavelengths are refracted directly out of the module, while the desirable (UV and visible) wavelengths are reflected at an angle into the transparent waveguide substrate, and the UV wavelengths are absorbed by the luminescent material in the wavelength conversion layer and re-emitted from the wavelength conversion layer at a wavelength in the visible light spectrum, and the transparent waveguide concentrator then directs the visible wavelengths by total internal reflection into the solar energy conversion device, where they are converted into electricity, as illustrated in FIG. 5.

[122] The heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, as disclosed herein, is applicable for all different types of solar cell devices. Devices, such as a silicon- based device, a lll-V or ll-VI PN junction device, a Copper-Indium-Gallium-Selenium (CIGS) thin film device, an organic sensitizer device, an organic thin-film device, or a Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) thin-film device, may be used with the film. In some embodiments, the system comprises at least one photovoltaic device or solar cell comprising a Cadmium Sulfide/Cadmium Telluride solar cell. In some embodiments, the photovoltaic device or solar cell may be a Copper Indium Gallium Diselenide solar cell. In some embodiments, the photovoltaic or solar cell may be a lll-V or ll-VI PN junction device. In some embodiments, the photovoltaic or solar cell may be an organic sensitizer device. In some embodiments, the photovoltaic or solar cell may be an organic thin-film device. In some embodiments, the photovoltaic device or solar cell may be an amorphous Silicon (a-Si) solar cell. In some embodiments, the photovoltaic device or solar cell comprises a microcrystalline Silicon (μο-Si) solar cell. In some embodiments, the photovoltaic device or solar cell may be a crystalline Silicon (c-Si) solar cell.

[123] In some embodiments, additional materials may be used, such as glass plates or polymer layers. The materials may be used to encapsulate the holographic optical element(s), or they may be used to protect or encapsulate the solar cell and/or wavelength conversion layer. In some embodiments, glass plates selected from low iron glass, borosilicate glass, or soda-lime glass, may be used in the system. In some embodiments of the system, the composition of the glass plate or polymer layers may also further comprise a strong UV absorber to block harmful high energy radiation into the solar cell.

[124] In some embodiments of the system, additional materials or layers may be used such as edge sealing tape, frame materials, polymer materials, or adhesive layers to adhere additional layers to the system. In some embodiments, the system further comprises an additional polymer layer containing a UV absorber.

[125] In some embodiments of the system, the composition of the wavelength conversion layer further comprises a UV stabilizer, antioxidant, or absorber, which may act to block high energy irradiation and prevent photo- degradation of the chromophore compound. In some embodiments, the thickness of the wavelength conversion layer is between about 10 μιη and about 2 mm.

[126] Some embodiments of the heat blocking transparent composite further provide a means for binding the holographic optical element and the transparent waveguide substrate, and any additional layer in the film. In some embodiments, the film further comprises an adhesive layer. In some embodiments, an adhesive layer adheres the holographic optical elements to glass plates, polymer layers, or to the wavelength conversion layer. Various types of adhesives may be used. In some embodiments, the adhesive layer comprises a substance selected from the group consisting of rubber, acrylic, silicone, vinyl alkyl ether, polyester, polyamide, urethane, fluorine, epoxy, ethylene vinyl acetate, and/or combinations thereof. The adhesive may be permanent or non-permanent. In some embodiments, the thickness of the adhesive layer is between about 1 μιη and 100 μιη. In some embodiments, the refractive index of the adhesive layer is in the range of about 1 .4 to about 1 .7.

[127] In some embodiments, the wavelength conversion layer is formed by first synthesizing the chromophore/polymer solution in the form of a liquid or gel, applying the chromophore/polymer solution to a glass plate using standard methods of application, such as spin coating or drop casting, then curing the chromophore/polymer solution to a solid form (i.e., heat treating, UV exposure, etc.) as is determined by the formulation design. Once dry, the film may then be adhered to glass or polymer substrates. In some embodiments the wavelength conversion layer may be adhered to glass or polymer surfaces using an optically transparent and photostable adhesive and/or laminator.

[128] An object of this disclosure is to provide a heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, which may be suitable for application to building or vehicle windows or skylights. By using this heat blocking transparent composite, there may be a reduced solar heat transmittance with minimal visibility distortion.

[129] The following example embodiments are contemplated.

Embodiments

Embodiment 1 . A heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, wherein:

the transparent waveguide substrate comprises a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface; and

the holographic optical element is disposed on a surface of the transparent waveguide substrate, and the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out of the edge surface or the major top surface of the transparent waveguide substrate; and

the heat blocking transparent composite is transparent in at least one viewing angle.

Embodiment 2. The heat blocking transparent composite of embodiment 1 , wherein the heat blocking transparent composite is not coupled with a solar energy conversion device.

Embodiment 3. The heat blocking transparent composite of embodiment 1 or 2, wherein the heat blocking transparent composite has a thickness of from about 1 mm to about 6 mm.

Embodiment 4. The heat blocking transparent composite of embodiment 1 , 2, or 3, wherein the heat blocking transparent composite has an area of at least 500 cm².

Embodiment 5. The heat blocking transparent composite of embodiment 1 , 2, 3, or 4, wherein the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out of the major top surface of the transparent waveguide substrate.

Embodiment 6. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, or 5, wherein the film is transparent for a viewing angle of 0 degrees from normal to the major top surface of the transparent waveguide substrate.

Embodiment 7. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, or 6, wherein the film is transparent for a viewing angle of about +20 degrees to about -90 degrees from normal to the major top surface of the transparent waveguide substrate.

Embodiment 8. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, or 7, wherein the film is transparent for a viewing angle of about +50 degrees to about -90 degrees from normal to the major top surface of the transparent waveguide substrate.

Embodiment 9. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, or 8, wherein the film has a transmittance in at least one viewing angle of at least 70% for wavelengths of light between about 400 nm and 700 nm.

Embodiment 10. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, or 9, wherein the film has a transmittance in at least one viewing angle of at least 80% for wavelengths of light between about 400 nm and 700 nm. Embodiment 1 1. The heat blocking transparent composite of embodiments 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the diffractive structures of the holographic optical element vary throughout the length of the heat blocking transparent composite.

Embodiment 12. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, or 1 1 , wherein the holographic optical element is configured to diffract light incident on the system at angles of greater than about +80 degrees from the normal to the top surface of the transparent waveguide substrate.

Embodiment 13. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or 12, wherein the holographic optical element is configured to diffract light incident on the system at angles of greater than about +50 degrees from the normal to the top surface of the transparent waveguide substrate.

Embodiment 14. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, or 13, wherein the variation in the diffractive structures across the length of the holographic optical element are configured to increase the portion of photons reflected out of the top and edge surfaces of the transparent waveguide substrate.

Embodiment 15. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, or 14, wherein the holographic optical element is configured to diffract photons of different incident wavelengths at an angle that will allow reflection of said photons out the edge or top surface depending on the incident wavelength.

Embodiment 16. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, or 15, wherein the holographic optical element is configured to diffract photons in the visible light region at an angle that will allow reflection of said photons out of the top or edge surfaces of the transparent waveguide substrate.

Embodiment 17. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, or 16, wherein the holographic optical element is configured to diffract photons in the infrared light region at an angle that will allow said photons to reflect out of the top or edge surfaces of the transparent waveguide substrate.

Embodiment 18. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the holographic optical element is configured to diffract photons in the ultraviolet light region at an angle that will allow said photons to reflect out of the top or edge surfaces of the transparent waveguide substrate.

Embodiment 19. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, or 18, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +80 degrees from the normal to the top surface of the transparent waveguide substrate.

Embodiment 20. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, or 19, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +60 degrees from the normal to the top surface of the transparent waveguide substrate.

Embodiment 21. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, or 20, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +30 degrees from the normal to the top surface of the transparent waveguide substrate.

Embodiment 22. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 , wherein the holographic optical element is optimized for different orientations of the solar array depending upon the position in the building and/or latitude of its location.

Embodiment 23. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , or 22, wherein the holographic optical element comprises one or a multiplicity of materials.

Embodiment 24. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, or 23, wherein the holographic optical element is made of at least one material selected from the group consisting of dichromated gelatin, photopolymer, bleached and unbleached photo emulsion, nanoparticle doped photopolymer, or any combination thereof.

Embodiment 25. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, or 24, wherein the transparent waveguide substrate comprises transparent glass or polymer materials with a refractive index of between about 1 .4 and about 1 .7.

Embodiment 26. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, or 25, wherein the transparent waveguide substrate comprises one or multiple transparent layers.

Embodiment 27. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, or 26, wherein the transparent waveguide substrate comprises at least one layer formed from a substance selected from the group consisting of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane, polyacrylate, and combinations thereof.

Embodiment 28. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, or 27, wherein the transparent waveguide substrate comprises at least one layer made of one host polymer, a host polymer and a co-polymer, or multiple polymers.

Embodiment 29. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, or 28, wherein the transparent waveguide substrate comprises at least one layer of a transparent inorganic amorphous glass.

Embodiment 30. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, or 29, wherein the transparent waveguide substrate comprises at least one layer of a glass material selected from the group consisting of silicon dioxide, albite, crown, flint, low iron glass, borofloat, borosilicate glass, soda-lime glass, or any combination thereof.

Embodiment 31. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, or 30, wherein the transparent waveguide substrate further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range, and re-emit those photons at a different wavelength, wherein a portion of the re-emitted photons are internally reflected and refracted within the transparent waveguide substrate. Embodiment 32. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, or 31 , wherein the transparent waveguide substrate comprises a single layer, wherein said layer is a wavelength conversion layer, and wherein said wavelength conversion layer comprises a polymer matrix and at least one luminescent material.

Embodiment 33. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , or 32, wherein the transparent waveguide substrate comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and a luminescent material.

Embodiment 34. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, or 33, wherein the wavelength conversion layer or layers are in between glass or polymer plates, wherein the glass or polymer plates also act to reflect photons out the top or edge surfaces of the transparent waveguide substrate.

Embodiment 35. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, or 34, wherein the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also act to reflect photons out the top or edge surfaces of the transparent waveguide substrate.

Embodiment 36. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, or 35, wherein the transparent waveguide substrate comprises two or more luminescent materials.

Embodiment 37. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, or 36, wherein the transparent waveguide substrate comprises two or more wavelength conversion layers, wherein each of the wavelength conversion layers independently comprises a different luminescent material such that each of the wavelength conversion layers absorbs photons at a different wavelength range.

Embodiment 38. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, or 37, wherein at least one of the luminescent materials is a down-shifting luminescent material.

Embodiment 39. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, or 38, wherein the luminescent material absorbs photons in the UV wavelength region, and re-emits the photons in the visible wavelength region.

Embodiment 40. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, or 39, wherein two or more luminescent materials absorb photons in the UV wavelength region.

Embodiment 41. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, or 40, wherein the polymer matrix of the at least one wavelength conversion layer is formed from a substance selected from the group consisting of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane, polyacrylate, and combinations thereof.

Embodiment 42. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, or 41 , wherein the polymer matrix of the wavelength conversion layer may be made of one host polymer, a host polymer and a co-polymer, or multiple polymers.

Embodiment 43. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , or 42, wherein the refractive index of the polymer matrix material is in the range of about 1 .4 to about 1 .7. Embodiment 44. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, or 43, wherein at least one of the luminescent materials is present in the polymer matrix in an amount in the range of about 0.01 wt% to about 3.0 wt%.

Embodiment 45. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, or 44, wherein at least one of the luminescent materials is a quantum dot material.

Embodiment 46. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, or 45, wherein at least one of the luminescent materials is an organic compound.

Embodiment 47. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, or 46, wherein at least one of the luminescent materials is selected from perylene derivative dyes, benzotriazole derivative dyes, diazaborinine, or benzothiadiazole derivative dyes.

Embodiment 48. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, or 47, wherein at least one of the luminescent materials comprises a structure as given by the following general formula (I):

Embodiment 49. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, or 48, wherein at least one of the luminescent materials comprises a structure as given b the following general formula (ll-a) and (ll-b):

wherein:

R is selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted heteroalkyi, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R is an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyl, aryl, heterocycloalkyl, or heteroaryl;

R⁴, R⁵, and R⁶ are independently selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted heteroalkyi, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyi, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R⁴ and R⁵, or R⁴ and R⁶, or R⁵ and R⁶, or R⁴ and R⁵ and R⁶, together form an optionally substituted ring or an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyl, aryl, heterocyclalkyl, or heteroaryl; and

L is selected from the group consisting of optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted alkynylene, optionally substituted arylene, and optionally substituted heteroarylene.

Embodiment 50. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, or 49, wherein the wavelength conversion layer further comprises a UV stabilizer, antioxidant, or absorber.

Embodiment 51. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, or 50, wherein the thickness of the wavelength conversion layer is in the range of about 10 μιη to about 2 mm.

Embodiment 52. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, or 51 , wherein the system further comprises an additional polymer layer comprising a UV absorber.

Embodiment 53. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , or 52, further comprising means for binding the holographic optical element, the transparent waveguide concentrator, and any additional layer in the composite.

Embodiment 54. The heat blocking transparent composite of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , 52, or 53, wherein the luminescent material comprises:

EXAMPLES

[130] It has been discovered that embodiments of heat blocking transparent composites described herein are useful for reducing the solar heating that is transmitted through the window. These benefits are further shown by the following examples, which are intended to be illustrative of the embodiments of the disclosure, but are not intended to limit the scope or underlying principles in any way.

Example 1 - HOE

[131 ] A glass substrate was cut to about 7" x 7" square. The cut glass sheet was cleaned with soap (washing detergent) and water, and then dried by nitrogen gas at room temperature.

Prepare Dichromate Gelatin (DCG) solution

[132] In a light controlled (safe red light lamp) environment, 160 mL deionized (Dl) water was added to 24 g of 300 bloom gelatin (Great Lakes Gelatin, Greyslake, IL, USA) and soaked for about 1 hour. The mixture was then stirred at about 50 °C until the gelatin was completely melted/dissolved (e.g., about 30 min). 8 g of ammonium dichromate ((NH₄)₂Cr0₄) was dissolved in about 40 mL Dl water. This (NH₄)₂Cr0₄ solution was added slowly to the gelatin solution and mixed for about 30 min at room temperature. The (NH₄)₂Cr0₄/gelatin mixture was filtered through a commercially available coffee filter paper. The filtered solution was kept in 50 °C water bath to prevent solidification.

Glass substrate coating

[133] In a light controlled (safe red light lamp) environment, the cleaned and dried glass substrate sample was blown with N₂ gas (room temperature for about 30 sec) and heated to about 60 °C. The heated plate was spin-coated with about 6 tbsp filtered-DCG solution at about 85 rpm for about 5 min. The coated-glass substrate was then dried at about 50% humidity and about 20 °C for about 20 h. The thickness of the film was about 8 to 10 μιη.

Recording of Hologram

[134] The DCG coated glass substrate was then cut into multiple 2" x 2" pieces. An index matching liquid was applied between the DCG film and the base of an isosceles right prism. The DCG film was then exposed to two expanded (about 3" diameter) coherent 2W 532 nm laser beam (Coherent Verdi 5W) for about 60 s. Beam 1 (object beam) that incidents from 13° to the normal of the right leg of the isosceles right prism has planar wavefront (Collimated beam). Beam 2 (reference beam) that incidents from -26° to the normal of the right leg of the isosceles right prism has cylindrical wavefront. A hologram was formed by recording interferometric pattern on the DCG-film based on the interference between the incident object laser beam and the incident reference laser beam.

Development of Heat blocking transparent composite

[135] After recording, the DCG-film coated glass was detached from the mirror and was developed in Kodak Fixer™ solution for about 1 min and then rinsed about 3 min through a running Dl water bath.

[136] The substrate was then, sequentially rinsed in IPA water solutions

(25/75, 50/50, 75/25, 90/10, and 100/0) for about 30 s for each bath. The film was then dried in an 80 °C chamber with a N₂ gas flow of about 30 CFM for about 10 min. The dried film was then (removed) scratched about 2 mm about the entire perimeter of the film. A second 2" x 2" inch glass substrate, prepared as described earlier, was heated at about 85 °C for about 10 min. About 0.2 mL of UV curable epoxy (NOA86H™, Norland Products, Inc., Cranbury, NJ, USA) was placed on the surface of the (dried film) second prepared glass substrate. The dried film was then deposited between the first and second glass substrates at room temperature with (until excess UV epoxy (and air bubbles) squeeze out any pressure/No heat) pressure and laminated. The laminated sample was then cured with about 10 mW/cm² ultraviolet light (about 360 nm) (LOCKTITE®, Dusseldorf, Germany) for about 2 min. [137] To measure the solar heat blocking, the Example 1 - HOE film was laminated to a 6.5 mm thick Borofloat® glass substrate by NOA86H™ epoxy and was placed vertically, facing due south. A black separate object was placed on the opposite side of the incident solar radiation in the shade. The temperature of the black object was measured throughout the day. FIG. 6 shows the temperature throughout the day of the black object exposed to only light transmitted through the Example 1 - HOE film.

Synthesis of Chromophore Compounds

Intermediate A

[138] Common Intermediate A was synthesized according to the following scheme.

Step 1 : 2-lsobutyl-2H-benzok/lM .2.31triazole.

[139] A mixture of benzotriazole (1 1 .91 g, 100 mmol), 1 -iodo-2- methylpropane (13.8 mL, 120 mmol), potassium carbonate (41 .46 g, 300 mmol), and dimethylformamide (200 mL) was stirred and heated under argon at 40 °C for 2 d. The reaction mixture was poured into ice/water (1 L) and extracted with toluene/hexanes (2:1 , 2 x 500 mL). The extract was washed with 1 N HCI (2 x 200 mL) followed by brine (100 mL), dried over anhydrous magnesium sulfate. The solvent was then removed under reduced pressure. The residue was triturated with hexane (200 mL) and set aside at room temperature for 2 h. The precipitate was separated and discarded, and the solution was filtered through a layer of silica gel (200 g). The silica gel was washed with hexane/dichloromethane/ethyl acetate (37:50:3, 2 L). The filtrate and washings were combined, and the solvent was removed under reduced pressure to give 2-isobutyl-2/-/-benzo[d][1 ,2,3]triazole (8.81 g, 50% yield) as an oily product. ¹ H NMR (400 MHz, CDCI₃): δ 7.86 (m, 2H, benzotriazole), 7.37 (m, 2H, benzotriazole), 4.53 (d, J = 7.3 Hz, 2H, /-Bu), 2.52 (m, 1 H, /-Bu), 0.97 (d, J = 7.0 Hz, 6H, /-Bu). Step 2: 4,7-Dibromo-2-isobutyl-2H-benzorc iri ,2,31triazole (Intermediate A).

[140] A mixture of 2-isobutyl-2H-benzo[c/][1 ,2,3]triazole (8.80 g, 50 mmol), bromine (7.7 mL, 150 mmol) and 48% HBr (50 mL) was heated at 130 °C for 24 h under a reflux condenser connected with an HBr trap. The reaction mixture was poured into ice/water (200 mL), treated with 5 N NaOH (100 mL) and extracted with dichloromethane (2 x 200 mL). The extract was dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. A solution of the residue in hexane/dichloromethane (1 :1 , 200 mL) was filtered through a layer of silica gel and concentrated to give 4,7-dibromo-2-isobutyl-2H-benzo[d][1 ,2,3]triazole, Intermediate A (1 1 .14 g, 63% yield) as an oil that slowly solidified upon storage at room temperature. ¹H NMR (400 MHz, CDCI₃): δ 7.44 (s, 2H, benzotriazole), 4.58 (d, J = 7.3 Hz, 2H, /-Bu), 2.58 (m, 1 H, /-Bu), 0.98 (d, J = 6.6 Hz, 6H, /-Bu).

Compound 1

[141 ] Example Chromophore Compound 1 was synthesized according to the following reaction scheme.

4-/-BuOC₆H₄B(OH)₂

1

[142] A mixture of Intermediate A (1 .32 g, 4.0 mmol), 4- isobutoxyphenylboronic acid (1 .94 g, 10.0 mmol), tetrakis(triphenylphosphine)palladium(0) (1 .00 g, 0.86 mmol), solution of sodium carbonate (2.12 g, 20 mmol) in water (15 mL), butanol (50 mL), and toluene (30 mL) was vigorously stirred and heated under argon at 100 °C for 16 h. The reaction mixture was poured into water (300 mL), stirred for 30 min and extracted with toluene/ethyl acetate/hexane (5:3:2, 500 mL). The volatiles were removed under reduced pressure, and the residue was chromatographed (silica gel, hexane/dichloromethane, 1 :1 ). The separated product was recrystallized from ethanol to give pure 4,7-bis(4-isobutoxyphenyl)-2-isobutyl-2/-/-benzo[c/][1 ,2,3]triazole, Compound 1 (1 .57 g, 83% yield). ¹H NMR (400 MHz, CDCI₃): δ 7.99 (d, J = 8.7 Hz, 4H, 4-/-BuOC₆H₄), 7.55 (s, 2H, benzotriazole), 7.04 (d, J = 8.8 Hz, 4H, 4-/-BuOC₆H₄), 4.58 (d, J = 7.3 Hz, 2H, /-Bu), 3.79 (d, J = 6.6 Hz, 4H, 4-/-BuOC₆H₄), 2.59 (m, 1 H, /- Bu), 2.13 (m, 2H, 4-/-BuOC₆H₄), 1 .04 (d, J = 6.6 Hz, 12H, 4-/-BuOC₆H₄), 1 .00 (d, J = 6.6 Hz, 6H, /-Bu). UV-vis spectrum (PVB): A_max = 359 nm. Fluorimetry (PVB): A_max = 434 nm. FIG. 9 shows the absorption and emission spectrum for Compound 1 .

Synthesis of Wavelength Conversion Film

[143] In an embodiment, a wavelength conversion film (WLC) was fabricated as follows: (i) preparing a 20 wt% Ethylene Vinyl Acetate (EVA purchased from Sigma-Aldrich, St. Louis, MO, USA and used as received) polymer solution with dissolved polymer powder in cyclopentanone; (ii) preparing the chromophore containing a EVA matrix by mixing the EVA polymer solution with the synthesized Chromophore Compound (Compound 1 ) at a weight ratio of Chromophore/EVA of 0.3 wt%, to obtain a chromophore-containing polymer solution; (iii) stirring the solution for approximately 30 min; (iv) then forming the chromophore/polymer film by directly drop casting the dye-containing polymer solution onto a substrate, then allowing the film to dry at room temperature over night followed by heat treating the film at 60 °C under vacuum for 10 min, to completely remove the remaining solvent, and (v) hot pressing the dry composition under vacuum to form a bubble-free film with film thickness of approximately 0.3 mm.

Example 2 - HOE/WLC

[144] A second heat blocking transparent composite was prepared in a manner similar to the Example 1 film described above, except that the device also comprised the WLC film, which was deposited on top of the HOE film, similar to the structure shown in FIG. 4. The solar heat blocking effect was also measured similar to the Example 1 film, and is shown in FIG. 7.

[145] The total transmittance of the Example 2 - HOE/WLC film was measured by Shimadzu UV3300™ (Shimadzu, Japan). First, continuous spectrum light irradiated from a halogen lamp source at 150 W (MC2563™, Otsuka Electronics, Inc., Japan) with no sample in the sample holder to obtain air reference transmission data. Next the sample (Example 2- HOE/WLC) was placed in the sample holder and irradiated with the same halogen lamp source. The transmitted spectrum was acquired for each sample by the multi-channel photo detector. FIG. 8 shows the transmittance versus wavelength of the Example 2 - HOE/WLC film.

Comparative Example 3 - Penjerex®

[146] A comparative transparent substrate film Penjerex® was obtained from

Nitto Denko (Osaka, Japan) and used as received. It was laminated to a 6.5 mm thick Borofloat® glass substrate by NOA86H™ epoxy and was placed vertically, facing due south and a black object was placed on the opposite side of the incident solar radiation. FIG. 8 shows the transmittance versus wavelength of the Comparative Example 3 - Penjerex® film.

Example 4 - HOE/WLC/Penierex®

[147] A heat blocking transparent composite was prepared in a manner similar to the Example 2 film described above, except that the Penjerex® film was laminated on the backside of glass substrate. The HOE/WLC/Penjerex® film was laminated to a 6.5 mm thick Borofloat® glass substrate by NOA86H™ epoxy and was placed vertically; facing due south and a black object was placed on the opposite side of the incident solar radiation. The solar heat blocking effect was measured similar to the Example 1 film, and is shown in FIG. 6. FIG. 8 shows the transmittance versus wavelength of the Example 4 - HOE/WLC/Penjerex® film.

Comparative Example 5 - 3M Amber 35

[148] A comparative transparent substrate film 3M™ Amber 35 was purchased from 3M™ and used as received. It was laminated to a 6.5mm thick Borofloat® glass substrate by NOA86H™ epoxy and was placed vertically; facing due south and a black object was placed on the opposite side of the incident solar radiation. The solar heat blocking effect was measured similar to the Example 1 film, and is shown in FIGS. 6 and 7. FIG. 8 shows the transmittance versus wavelength of the Comparative Example 5 - 3M™ Amber 35 film.

Comparative Example 6 - Bare Glass

[149] A comparative Borofloat® bare glass with 6.5 mm thickness was purchased from Howard Glass (Worcester, MA, USA) and used as received. The solar heat blocking effect was measured similar to the Example 1 film, and is shown in FIGS. 6 and 7. FIG. 8 shows the transmittance versus wavelength of the Comparative Example 7 - Bare Glass. FIG. 9 shows the light transmittance versus wavelength spectra for HOE/WLC heat blocking film from 90° (normal viewing light) incident angle and 50° (sun light angle) incident angle, respectively.

[150] As shown in FIG. 9, the film with holographic optical elements and wavelength conversion film maintain over 80-85% transparency throughout about 400 nm to about 1000 nm region at normal viewing angle 90°. When the light incidents from 50° (typical sun light angle), over 70% of near-infrared (NIR) (about 700 nm to about 1000 nm) photons, over 50% of visible (about 400 nm to about 700 nm) photons was guided by holographic optical elements towards the edge of the substrate. The UV (about 200 nm to about 400 nm) photons was absorbed by wavelength conversion layer and reemitted to longer wavelength (about 400 nm to about 500 nm) photons and guided towards the substrate edge. Because large portion of the solar irradiation beam was guided towards other directions instead of direct transmitted inside the glass substrate, significant reduction of solar heating effect is observed.

[151 ] As shown in FIGS. 6-8, the films with the holographic optical elements were able to block significantly more heat than the commercially available films. The films with the holographic optical elements also showed better transmittance of light at all visible wavelengths than the comparative example films.

[152] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[153] The terms "a," "an," "the" and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of any claim. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[154] Groupings of alternative elements or embodiments disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[155] Certain embodiments are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, the claims include all modifications and equivalents of the subject matter recited in the claims as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is contemplated unless otherwise indicated herein or otherwise clearly contradicted by context.

[156] In closing, it is to be understood that the embodiments disclosed herein are illustrative of the principles of the claims. Other modifications that may be employed are within the scope of the claims. Thus, by way of example, but not of limitation, alternative embodiments may be utilized in accordance with the teachings herein. Accordingly, the claims are not limited to embodiments precisely as shown and described.

Claims

WHAT IS CLAIMED IS:

1 . A heat blocking transparent composite comprising a holographic optical element and a transparent waveguide substrate, wherein:

2. the transparent waveguide substrate comprises a major top surface for receipt of solar radiation, a bottom surface, and at least one edge surface; and

3. the holographic optical element is disposed on a surface of the transparent waveguide substrate, and the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out of the edge surface or the major top surface of the transparent waveguide substrate; and

4. The heat blocking transparent composite is transparent in at least one viewing angle.

5. The heat blocking transparent composite of claim 1 , wherein the heat blocking transparent composite is not coupled with a solar energy conversion device.

6. The heat blocking transparent composite of claim 1 or 2, wherein the heat blocking transparent composite has a thickness of from about 1 mm to about 6 mm.

7. The heat blocking transparent composite of claim 1 , 2, or 3, wherein the heat blocking transparent composite has an area of at least 500 cm².

8. The heat blocking transparent composite of claim 1 , 2, 3, or 4, wherein the holographic optical element is configured to diffract a portion of incident light at an angle that allows reflection of the light out of the major top surface of the transparent waveguide substrate.

9. The heat blocking transparent composite of claim 1 , 2, 3, 4, or 5, wherein the film is transparent for a viewing angle of 0 degrees from normal to the major top surface of the transparent waveguide substrate.

10. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, or 6, wherein the film is transparent for a viewing angle of about +20 degrees to about -90 degrees from normal to the major top surface of the transparent waveguide substrate.

1 1 . The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, or 7, wherein the film is transparent for a viewing angle of about +50 degrees to about -90 degrees from normal to the major top surface of the transparent waveguide substrate.

12. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, or

8, wherein the film has a transmittance in at least one viewing angle of at least 70% for wavelengths of light between about 400 nm and 700 nm.

13. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, or 9, wherein the film has a transmittance in at least one viewing angle of at least 80% for wavelengths of light between about 400 nm and 700 nm.

14. The heat blocking transparent composite of claims 1 , 2, 3, 4, 5, 6, 7, 8,

9, or 10, wherein the diffractive structures of the holographic optical element vary throughout the length of the heat blocking transparent composite.

15. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, or 1 1 , wherein the holographic optical element is configured to diffract light incident on the system at angles of greater than about +80 degrees from the normal to the top surface of the transparent waveguide substrate.

16. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or 12, wherein the holographic optical element is configured to diffract light incident on the system at angles of greater than about +50 degrees from the normal to the top surface of the transparent waveguide substrate.

17. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, or 13, wherein the variation in the diffractive structures across the length of the holographic optical element are configured to increase the portion of photons reflected out of the top and edge surfaces of the transparent waveguide substrate.

18. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, or 14, wherein the holographic optical element is configured to diffract photons of different incident wavelengths at an angle that will allow reflection of said photons out the edge or top surface depending on the incident wavelength.

19. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, or 15, wherein the holographic optical element is configured to diffract photons in the visible light region at an angle that will allow reflection of said photons out of the top or edge surfaces of the transparent waveguide substrate.

20. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, or 16, wherein the holographic optical element is configured to diffract photons in the infrared light region at an angle that will allow said photons to reflect out of the top or edge surfaces of the transparent waveguide substrate.

21 . The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the holographic optical element is configured to diffract photons in the ultraviolet light region at an angle that will allow said photons to reflect out of the top or edge surfaces of the transparent waveguide substrate.

22. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, or 18, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +80 degrees from the normal to the top surface of the transparent waveguide substrate.

23. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, or 19, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +60 degrees from the normal to the top surface of the transparent waveguide substrate.

24. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, or 20, wherein the holographic optical element is configured to diffract visible light incident on the system at angles of greater than about +30 degrees from the normal to the top surface of the transparent waveguide substrate.

25. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 , wherein the holographic optical element is optimized for different orientations of the solar array depending upon the position in the building and/or latitude of its location.

26. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , or 22, wherein the holographic optical element comprises one or a multiplicity of materials.

27. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, or 23, wherein the holographic optical element is made of at least one material selected from the group consisting of dichromated gelatin, photopolymer, bleached and unbleached photo emulsion, nanoparticle doped photopolymer, or any combination thereof.

28. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, or 24, wherein the transparent waveguide substrate comprises transparent glass or polymer materials with a refractive index of between about 1 .4 and about 1 .7.

29. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, or 25, wherein the transparent waveguide substrate comprises one or multiple transparent layers.

30. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, or 26, wherein the transparent waveguide substrate comprises at least one layer formed from a substance selected from the group consisting of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol- gel, polyurethane, polyacrylate, and combinations thereof.

31 . The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, or 27, wherein the transparent waveguide substrate comprises at least one layer made of one host polymer, a host polymer and a co-polymer, or multiple polymers.

32. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, or 28, wherein the transparent waveguide substrate comprises at least one layer of a transparent inorganic amorphous glass.

33. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, or 29, wherein the transparent waveguide substrate comprises at least one layer of a glass material selected from the group consisting of silicon dioxide, albite, crown, flint, low iron glass, borofloat, borosilicate glass, soda-lime glass, or any combination thereof.

34. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, or 30, wherein the transparent waveguide substrate further comprises a luminescent material, wherein said luminescent material acts to absorb incident photons of a particular wavelength range, and re-emit those photons at a different wavelength, wherein a portion of the re-emitted photons are internally reflected and refracted within the transparent waveguide substrate.

35. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, or

31 , wherein the transparent waveguide substrate comprises a single layer, wherein said layer is a wavelength conversion layer, and wherein said wavelength conversion layer comprises a polymer matrix and at least one luminescent material.

36. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , or 32, wherein the transparent waveguide substrate comprises two or more transparent layers, wherein at least one of the layers is a wavelength conversion layer, wherein said wavelength conversion layer comprises a polymer matrix and a luminescent material.

37. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 ,

32, or 33, wherein the wavelength conversion layer or layers are in between glass or polymer plates, wherein the glass or polymer plates also act to reflect photons out the top or edge surfaces of the transparent waveguide substrate.

38. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, or 34, wherein the wavelength conversion layer or layers may be on top of or on bottom of a glass or polymer plate, wherein the glass or polymer plate also act to reflect photons out the top or edge surfaces of the transparent waveguide substrate.

39. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, or 35, wherein the transparent waveguide substrate comprises two or more luminescent materials.

40. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, or 36, wherein the transparent waveguide substrate comprises two or more wavelength conversion layers, wherein each of the wavelength conversion layers independently comprises a different luminescent material such that each of the wavelength conversion layers absorbs photons at a different wavelength range.

41 . The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, or 37, wherein at least one of the luminescent materials is a down-shifting luminescent material.

42. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, or 38, wherein the luminescent material absorbs photons in the UV wavelength region, and re-emits the photons in the visible wavelength region.

43. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, or 39, wherein two or more luminescent materials absorb photons in the UV wavelength region.

44. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, or 40, wherein the polymer matrix of the at least one wavelength conversion layer is formed from a substance selected from the group consisting of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane, polyacrylate, and combinations thereof.

45. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, or 41 , wherein the polymer matrix of the wavelength conversion layer may be made of one host polymer, a host polymer and a co-polymer, or multiple polymers.

46. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , or 42, wherein the refractive index of the polymer matrix material is in the range of about 1 .4 to about 1 .7.

47. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, or 43, wherein at least one of the luminescent materials is present in the polymer matrix in an amount in the range of about 0.01 wt% to about 3.0 wt%.

48. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, or 44, wherein at least one of the luminescent materials is a quantum dot material.

49. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, or 45, wherein at least one of the luminescent materials is an organic compound.

50. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, or 46, wherein at least one of the luminescent materials is selected from perylene derivative dyes, benzotriazole derivative dyes, diazaborinine, or benzothiadiazole derivative dyes.

51 . The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, or 47, wherein at least one of the luminescent materials comprises a structure as given by the following general formula (I):

wherein R-i, R₂, and R3 comprise and alkyl, a substituted alkyl, or an aryl.

52. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, or 48, wherein at least one of the luminescent materials comprises a structure as given by the following general formula (ll-a) and (ll-b):

wherein:

R is selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyi, optionally substituted heteroalkyi, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R is an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyi, aryl, heterocycloalkyl, or heteroaryl;

R⁴, R⁵, and R⁶ are independently selected from the group consisting of optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyi, optionally substituted heteroalkyi, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxyalkyl, optionally substituted heteroalkenyl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyi, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl, optionally substituted ether, optionally substituted ketone, optionally substituted sulfone, and optionally substituted sulfonamide; or R⁴ and R⁵, or R⁴ and R⁶, or R⁵ and R⁶, or R⁴ and R⁵ and R⁶, together form an optionally substituted ring or an optionally substituted polycyclic ring system, wherein each ring is independently cycloalkyi, aryl, heterocyclalkyi, or heteroaryl; and

53. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, or 49, wherein the wavelength conversion layer further comprises a UV stabilizer, antioxidant, or absorber.

54. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, or 50, wherein the thickness of the wavelength conversion layer is in the range of about 10 μιη to about 2 mm.

55. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, or 51 , wherein the system further comprises an additional polymer layer comprising a UV absorber.

56. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , or 52, further comprising means for binding the holographic optical element, the transparent waveguide concentrator, and any additional layer in the composite.

57. The heat blocking transparent composite of claim 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , 52, or 53, wherein the luminescent material comprises:

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