US3854070A - Electroluminescent device with variable emission - Google Patents

Electroluminescent device with variable emission Download PDF

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US3854070A
US3854070A US00319046A US31904672A US3854070A US 3854070 A US3854070 A US 3854070A US 00319046 A US00319046 A US 00319046A US 31904672 A US31904672 A US 31904672A US 3854070 A US3854070 A US 3854070A
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electroluminescent
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S Zynio
Z Pukhly
N Vlasenko
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H05B33/26—Light sources with substantially two-dimensional radiating surfaces characterised by the composition or arrangement of the conductive material used as an electrode
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H05B33/22—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers

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  • An electroluminescent device with variable emission colors comprises at least five layers applied onto a substrate in the following order: a first electrode; a protective layer made from a material transparent for emission, the protective layer having an index of refraction equal or close to that of the electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers; a layer of the electroluminescent substance; an insulating layer and a second electrode; one of the electrodes being partially transparent for luminescent emission; both electrodes having a high reflection coefficient and making up a Fabry-Perot cavity tunes in resonance to a prescribed emission wavelength; the thickness of the protective layer, the coefficient of diffusion of its material into the layer of the electroluminescent substance, and the coefficient of diffusion of the material of the first electrode into the protective layer being selected so that during thermal annealing of the electroluminescent layer there is no diffusion into the latter of either the substance of the first electrode
  • the invention relates generally to electroluminescent devices and more particularly, it relates to electroluminescent devices having variable emission colors and used, for instance, as light sources, electroluminescent condensers, etc.
  • an electroluminescent device with variable emission colors wherein a layer of sublimed electroluminescent substance is disposed between two electrodes, one of which is partially transparent and the other is opaque for the electroluminescent emission.
  • the electrodes are made of a highly reflective material and form a Fabry-Perot cavity while the thickness of the electroluminescent layer is multiple to the wavelength of emission with a given color, with the phase jump at the metal-dielectric junction being taken into account.
  • a disadvantage of the known device is that in the course of thermal annealing of the electroluminescent layer during the manufacture the substance of the partially transparent electrode diffuses into the luminophor layer applied directly onto this electrode.
  • the result of the diffusion is two-fold: first, it reduces the reflection index of the electrode and hence, spoils the Q-factor of the cavity; second, it lowers the efficiency of the output emission.
  • the object of the present invention is to modifythe design of an electroluminescent device with variable emission color so as to prevent the substance of the electrode from diffusing into the electroluminescent layer in the course of manufacture.
  • the object is achieved by providing at least five layers applied onto a substrate in the following order: a first electrode; a protective layer made from a material transparent for emission, the protective layer having an index of refraction equal or close to that of the electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers; a layer of the electroluminescent substance; an insulating layer and a second electrode; one of the electrodes being partially transparent for luminescent emission; both electrodes having a high reflection coefficient and making up a Fabry-Perot cavity tuned in resonance to a prescribed emission wavelength; the thickness of the protective layer, the coefficient of diffusion of its material into the layer of the electroluminescent substance, and the coefficient of diffusion of the material of the first electrode into the protective layer being selected so that during thermal annealing of the electrolumin
  • electroluminescent layer is a film of ZnS: Mn applied in vacuum
  • the partially transparent first electrode is a film of gold
  • the non-transparent second electrode is a film of aluminum
  • the protective layer is a film of unalloyed ZnS subjected to crystallization
  • the insulating layer is a film of SiO.
  • the electroluminescent device designed according to the present invention is simple in production, and the thermal annealing of the electroluminescent layer involves no diffusion of the electrode substance into the luminophor layer which makes it possible to obtain high quality devices that exhibit distinctly variable emission colors having their absolute brightness sufficiently high for practical applications.
  • the device shown in the drawing comprises a dielectric substrate 1 (glass, quartz, etc.).
  • the latter should be transparent for the emission.
  • an electrode 2 having a high reflection index (R 2 65 percent) made of, say, AuTA g Mn.
  • a protective layer 3 made of a substance which is optically transparent for emission and characterized by a refraction index whose value approaches that of the luminophor.
  • the diffusion properties and the thickness of the layer 3 are selected so that no diffusion occurs into the luminophor layer of either the substance of the electrode 2 or the material of the protective layer 3 in the course of thermal treatment.
  • the substance of the layer 3 is resistant to chemical reactions with the materials of the adjacent layers; the coefficient of diffusion of the electrode substance into the layer 3 and the coefficient of diffusion of the layers components into the electroluminescent layer are low.
  • the layer 3 is made as a film of insulating oxides, such as Ta O SiO.
  • the protective layer 3 be made of a substance used as the basis of the luminophor but without doping impurities, for instance ZnS.
  • the indices of refraction of such substances are equal to that of the luminophor, thus making them optically homogeneous with respect to multi-beam interference.
  • the substance of the protective layer 3 is subjected to crystallization.
  • This layer is made as thin as possible so as to reduce the voltage drop across it and to keep the electrical loss in the electroluminescent device to the minimum.
  • the layer 3 is coated with an electroluminescent layer 4 the optical thickness of which together with that of the protective layer 3 satisfy the interference relationship for the maximum emission at a given wavelength and a given viewing angle with the phase jump at the metaldielectric junction being taken into account;
  • an insulator layer 5 which is 20-25 nm thick and which protects the device from shortcircuits and plays but a minor role in the multi-beam interference process due to its negligible thickness.
  • a second electrode 6 having a high index of reflection.(R B 65 percent).
  • the device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made as an Au-film 50 to 60 nm thick, an undoped ZnS-layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a ZnS:Mn-film the thickness of which together with that of the protective layer 3 satisfy the interference relationship, an insulation layer 5 made of SiO to 35 nm thick and an opaque electrode 6 made of an Ai-film.
  • A is the emission wavelength
  • the device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made as an Au-film 50 to 60 nm thick, an undoped ZnS layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a ZnS:Er-film the thickness of which satisfies the interference relationship, a SiO- insulation layer 5 which is from 20 to 35 nm thick and an opaque electrode 6 made of an Al-film.
  • the device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made of 14 Au-film 50 to 60 nm thick, an undoped ZnSe protection layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a Zn SezMn-film the thickness of which satisfies the interference relationship, an insulation SiO layer 5 which is from 20-35 nm thick and an opaque electrode .6 made of an Al-film.
  • a layer of gold 50 to 60 nm thick is evaporated under a vacuum of 1.10 to 2.10 torr onto a glass substrate 1 which has been cleaned beforehand. Then a film of undoped ZnS to nm thick is applied onto the gold layer.
  • the two-step procedure is as follows.
  • the undoped electroluminescent material is sprayed onto a cold substrate by means of evaporation in avacuum of 1.10" to 2.10 torr.
  • an activator for example, Mn
  • Mn an activator
  • the activator material is evaporated in the form of a chemically pure metal of a predetermined weight calculated on the basis of the required activator concentration, for instance, 1 to 5 percent in the case of Mn.
  • another layer of undoped electroluminescent substance (ZnS) is sprayed and the device is subjected to a thermal annealing for example at 650 to 700C during 5-15 minutes in the case of ZnS:Mn. Under these conditions the electroluminescent film is crystallized and simultaneously the activator diffuses into it, the diffusion being uniform in thickness.
  • Applied onto the electroluminescentfilm by means of vacuum evaporation are the SiO insulation layer and the opaque electrode of an Al-film.
  • An electroluminescent device having variable emission colors comprising:
  • At least five layers comprising, and being disposed onto said substrate in the following order:
  • a protective layer being formed from a material which is transparent to luminescent emission
  • a layer of electroluminescent substance said protective layer having an index of refraction which is substantially equal to that of said electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers;
  • a second electrode e. a second electrode, one of said electrodes being partially transparent for luminescent emission, said first and second electrodes having a high reflection coefficient and forming a Fabry-Perot cavity tuned in resonance to a prescribed emission wavelength; the thickness of said protective layer, the coefiicient of diffusion of the material of said protective layer into said layer of said electroluminescent substance and the coefficient of diffusion of the material of said first electrode into said protective layer being selected so that at the temperature of thermal annealing of said layer of said electroluminescent substances there is no diffusion into said layer of said electroluminescent substance from either the material of said first electrode or the material of said protective layer.

Abstract

An electroluminescent device with variable emission colors, comprises at least five layers applied onto a substrate in the following order: a first electrode; a protective layer made from a material transparent for emission, the protective layer having an index of refraction equal or close to that of the electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers; a layer of the electroluminescent substance; an insulating layer and a second electrode; one of the electrodes being partially transparent for luminescent emission; both electrodes having a high reflection coefficient and making up a Fabry-Perot cavity tunes in resonance to a prescribed emission wavelength; the thickness of the protective layer, the coefficient of diffusion of its material into the layer of the electroluminescent substance, and the coefficient of diffusion of the material of the first electrode into the protective layer being selected so that during thermal annealing of the electroluminescent layer there is no diffusion into the latter of either the substance of the first electrode or the substance of the protective layer.

Description

United States Patent Vlasenko et al.
[4 1 Dec. 10, 1974 ELECTROLUMINESCENT DEVICE WITH VARIABLE EMISSION [76] Inventors: Natalya Andreevna Vlasenko, ulitsa Entuziastsov, 15, kv. 175; Stepan Andreevich Zynio, prospekt Nauki, 142, korpus 14, kv. 24/4; Zhanetta Alexandrovna Pukhly, bulvar Druzhby narodov, 3b, kv. 79, all of Kiev, USSR.
[22] Filed: Dec. 27, 1972 [21] Appl. No.: 319,046
[52] US. Cl 313/503, 313/112, 313/509 [51] Int. Cl. H05b 33/22, H05b 33/26 [58] Field of Search 313/108 A, 108 D, 112;
[ 5 6 References Cited UNITED STATES PATENTS 2,887,402 5/1959 Ballard 313/108 A X 3,046,432 7/1962 Nehrich, Jr. 313/108 A 3,175,116 3/1965 Feuer 313/108 A 3,248,669 4/1966 Dumke et al. 331/945 H 3,268,755 8/1966 Reschauer 313/108 A 3,560,784 2/1971 Steele et a1. 313/108 A 3,576,356 4/1971 Hyman et al. 313/112 X OTHER PUBLICATIONS Electroluminescence and Semiconductor Lasers, by Henry F. lvey, IEEE Journal of Quantum Electronics,
Vol. QE-2, No. 11, November 1966, pages 713-726.
Primary Examiner-Palmer C. Demeo Attorney, Agent, or Firm--Holman & Stern [5 7] ABSTRACT An electroluminescent device with variable emission colors, comprises at least five layers applied onto a substrate in the following order: a first electrode; a protective layer made from a material transparent for emission, the protective layer having an index of refraction equal or close to that of the electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers; a layer of the electroluminescent substance; an insulating layer and a second electrode; one of the electrodes being partially transparent for luminescent emission; both electrodes having a high reflection coefficient and making up a Fabry-Perot cavity tunes in resonance to a prescribed emission wavelength; the thickness of the protective layer, the coefficient of diffusion of its material into the layer of the electroluminescent substance, and the coefficient of diffusion of the material of the first electrode into the protective layer being selected so that during thermal annealing of the electroluminescent layer there is no diffusion into the latter of either the substance of the first electrode or the substance of the protective layer.
2 Claims, 1 Drawing Figure \\\'\\\\\\\\txxaxxi siixsxsse,
f f, -l
f, f/ f/ ELECTROLUMINESCENT DEVICE WITH VARIABLE EMISSION BACKGROUND OF THE INVENTION The invention relates generally to electroluminescent devices and more particularly, it relates to electroluminescent devices having variable emission colors and used, for instance, as light sources, electroluminescent condensers, etc.
Known in the art is an electroluminescent device with variable emission colors wherein a layer of sublimed electroluminescent substance is disposed between two electrodes, one of which is partially transparent and the other is opaque for the electroluminescent emission. The electrodes are made of a highly reflective material and form a Fabry-Perot cavity while the thickness of the electroluminescent layer is multiple to the wavelength of emission with a given color, with the phase jump at the metal-dielectric junction being taken into account.
A disadvantage of the known device is that in the course of thermal annealing of the electroluminescent layer during the manufacture the substance of the partially transparent electrode diffuses into the luminophor layer applied directly onto this electrode.
The result of the diffusion is two-fold: first, it reduces the reflection index of the electrode and hence, spoils the Q-factor of the cavity; second, it lowers the efficiency of the output emission.
SUMMARY OF THE INVENTION The object of the present invention is to modifythe design of an electroluminescent device with variable emission color so as to prevent the substance of the electrode from diffusing into the electroluminescent layer in the course of manufacture. The object is achieved by providing at least five layers applied onto a substrate in the following order: a first electrode; a protective layer made from a material transparent for emission, the protective layer having an index of refraction equal or close to that of the electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers; a layer of the electroluminescent substance; an insulating layer and a second electrode; one of the electrodes being partially transparent for luminescent emission; both electrodes having a high reflection coefficient and making up a Fabry-Perot cavity tuned in resonance to a prescribed emission wavelength; the thickness of the protective layer, the coefficient of diffusion of its material into the layer of the electroluminescent substance, and the coefficient of diffusion of the material of the first electrode into the protective layer being selected so that during thermal annealing of the electroluminescent layer there is no diffusion into the latter of either the substance of the first electrode or the substance of the protective layer.
It is also possible to provide an electroluminescent device, wherein the electroluminescent layer is a film of ZnS: Mn applied in vacuum, the partially transparent first electrode is a film of gold, the non-transparent second electrode is a film of aluminum, the protective layer is a film of unalloyed ZnS subjected to crystallization, and the insulating layer is a film of SiO.
The electroluminescent device designed according to the present invention is simple in production, and the thermal annealing of the electroluminescent layer involves no diffusion of the electrode substance into the luminophor layer which makes it possible to obtain high quality devices that exhibit distinctly variable emission colors having their absolute brightness sufficiently high for practical applications.
BRIEF DESCRIPTION OF THE DRAWING The invention will now be described by way of example with reference to the accompanying drawing which shows a cross section of an electroluminescent device with variable emission colors according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The device shown in the drawing comprises a dielectric substrate 1 (glass, quartz, etc.).
In case the emission is brought out through a substrate l, the latter should be transparent for the emission. Applied onto the substrate 1 by any known procedure (e.g., by vacuum evaporation, cathode spraying or chemical deposition) is an electrode 2 having a high reflection index (R 2 65 percent) made of, say, AuTA g Mn. Applied directly onto an electrode 2 is a protective layer 3 made of a substance which is optically transparent for emission and characterized by a refraction index whose value approaches that of the luminophor. The diffusion properties and the thickness of the layer 3 are selected so that no diffusion occurs into the luminophor layer of either the substance of the electrode 2 or the material of the protective layer 3 in the course of thermal treatment. The substance of the layer 3 is resistant to chemical reactions with the materials of the adjacent layers; the coefficient of diffusion of the electrode substance into the layer 3 and the coefficient of diffusion of the layers components into the electroluminescent layer are low.
Preferably the layer 3 is made as a film of insulating oxides, such as Ta O SiO.
It is more preferable that the protective layer 3 be made of a substance used as the basis of the luminophor but without doping impurities, for instance ZnS. The indices of refraction of such substances are equal to that of the luminophor, thus making them optically homogeneous with respect to multi-beam interference.
To reduce the coefficient of diffusion, the substance of the protective layer 3 is subjected to crystallization.
This layer is made as thin as possible so as to reduce the voltage drop across it and to keep the electrical loss in the electroluminescent device to the minimum.
Then, using any of the known procedures, the layer 3 is coated with an electroluminescent layer 4 the optical thickness of which together with that of the protective layer 3 satisfy the interference relationship for the maximum emission at a given wavelength and a given viewing angle with the phase jump at the metaldielectric junction being taken into account; Placed onto the layer 4 is an insulator layer 5 which is 20-25 nm thick and which protects the device from shortcircuits and plays but a minor role in the multi-beam interference process due to its negligible thickness. Applied onto the layer 5 is a second electrode 6 having a high index of reflection.(R B 65 percent). The electhe technological procedure employed in the manufacture of the devices given by way of examples.
EXAMPLE 1 The device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made as an Au-film 50 to 60 nm thick, an undoped ZnS-layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a ZnS:Mn-film the thickness of which together with that of the protective layer 3 satisfy the interference relationship, an insulation layer 5 made of SiO to 35 nm thick and an opaque electrode 6 made of an Ai-film.
The interference relationship is given by the expres- SlOl'l d is the total thickness of two films (the electroluminescent and the protective layers),
p. is the refraction index,
B is the viewing angle of the output emission,
m is the interference order,
A is the emission wavelength,
4),, (b are the phase jumps occuring when the emission is reflected from the electrodes.
By varying the thickness of the ZnS:Mn electroluminescent films, it is possible to obtain devices having a green glow (A 550 nm), orange \=585 nm) and red (A 640 nm).
EXAMPLE 2 The device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made as an Au-film 50 to 60 nm thick, an undoped ZnS layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a ZnS:Er-film the thickness of which satisfies the interference relationship, a SiO- insulation layer 5 which is from 20 to 35 nm thick and an opaque electrode 6 made of an Al-film.
EXAMPLE 3 The device comprises the following elements arranged in series: a glass substrate 1, an electrode 2 made of 14 Au-film 50 to 60 nm thick, an undoped ZnSe protection layer 3 which is from 120 to 180 nm thick, an electroluminescent layer 4 made of a Zn SezMn-film the thickness of which satisfies the interference relationship, an insulation SiO layer 5 which is from 20-35 nm thick and an opaque electrode .6 made of an Al-film.
The technological procedure involved in the manufacture of these devices is as follows.
A layer of gold 50 to 60 nm thick is evaporated under a vacuum of 1.10 to 2.10 torr onto a glass substrate 1 which has been cleaned beforehand. Then a film of undoped ZnS to nm thick is applied onto the gold layer.
After that the samples are annealed in vacuum at 550 to 600C for 5 to 15 minutes. This results in a crystallization of the undoped ZnS-film. Then a two-step spraying procedure is used to obtain a film of the electroluminescent material of the required thickness.
The two-step procedure is as follows.
The undoped electroluminescent material is sprayed onto a cold substrate by means of evaporation in avacuum of 1.10" to 2.10 torr. Then, an activator, for example, Mn, is introduced into the electroluminescent material by means of vacuum evaporation, the activator material being evaporated in the form of a chemically pure metal of a predetermined weight calculated on the basis of the required activator concentration, for instance, 1 to 5 percent in the case of Mn. Then, another layer of undoped electroluminescent substance (ZnS) is sprayed and the device is subjected to a thermal annealing for example at 650 to 700C during 5-15 minutes in the case of ZnS:Mn. Under these conditions the electroluminescent film is crystallized and simultaneously the activator diffuses into it, the diffusion being uniform in thickness.
Applied onto the electroluminescentfilm by means of vacuum evaporation are the SiO insulation layer and the opaque electrode of an Al-film.
What we claim is:
1. An electroluminescent device having variable emission colors, said device comprising:
a substrate; and
at least five layers comprising, and being disposed onto said substrate in the following order:
a. a first electrode;
b. a protective layer being formed from a material which is transparent to luminescent emission;
c. a layer of electroluminescent substance, said protective layer having an index of refraction which is substantially equal to that of said electroluminescent substance and being resistant to chemical reaction with the substances of the adjoining layers;
d. an insulating layer; and
e. a second electrode, one of said electrodes being partially transparent for luminescent emission, said first and second electrodes having a high reflection coefficient and forming a Fabry-Perot cavity tuned in resonance to a prescribed emission wavelength; the thickness of said protective layer, the coefiicient of diffusion of the material of said protective layer into said layer of said electroluminescent substance and the coefficient of diffusion of the material of said first electrode into said protective layer being selected so that at the temperature of thermal annealing of said layer of said electroluminescent substances there is no diffusion into said layer of said electroluminescent substance from either the material of said first electrode or the material of said protective layer.
2. An electroluminescent device as claimed in claim 1, wherein said layer of said electroluminescent substance comprises a film of ZnS:Mn applied in a vacuum, said first electrode comprises a film of gold, said second electrode comprises a film of aluminum, said protective layer comprises afilm of undoped ZnS subjected to crystallization, and said insulating layer comprises a film of SiO.

Claims (2)

1. AN ELECTROLUMINESCENT DEVICE HAVING VARIABLE EMISSION COLORS, SAID DEVICE COMPRISING: A SUBSTRATE; AND AT LEAST FIVE LAYERS COMPRISING, AND BEING DISPOSED ONTO SAID SUBSTRATE IN THE FOLLOWING ORDER: A. A FIRST ELECTRODE; B. A PROTECTIVE LAYER BEING FORMED FROM A MATERIAL WHICH IS TRANSPARENT TO LUMINESCENT EMISSION; C. A LAYER OF ELECTROLUMINESCENT SUBSTANCE, SAID PROTECTIVE LAYER HAVING AN INDEX OF REFRACTION WHICH IS SUBSTANTIALLY EQUAL TO THAT OF SAID ELECTROLUMINESCENT SUBSTANCE AND BEING RESISTANT TO CHEMICAL REACTION WITH THE SUBSTANCES OF THE ADJOINING LAYERS; D. AN INSULATING LAYER; AND E. A SECOND ELECTRODE, ONE OF SAID ELETRODES BEING PARTIALLY TRANSPARENT FOR LIMINESCENT EMISSION, SAID FIRST AND SECOND ELECTRODES HAVING A HIGH REFLECTION COEFFICIENT AND FORMING A FABRY-PEROT CAVITY TUNED IN RESONANCE TO A PRESCRIBED EMISSION WAVELENGTH; THE THICKNESS OF SAID PROTECTIVE LAYER, THE COEFFICIENT OF DIFFUSION
2. An electroluminescent device as claimed in claim 1, wherein said layer of said electroluminescent substance comprises a film of ZnS:Mn applied in a vacuum, said first electrode comprises a film of gold, said second electrode comprises a film of aluminum, said protective layer comprises a film of undoped ZnS subjected to crystallization, and said insulating layer comprises a film of SiO.
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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2369640A1 (en) * 1976-10-29 1978-05-26 Secr Defence Brit ELECTROLUMINESCENT PANELS
US4140937A (en) * 1975-07-22 1979-02-20 Aron Vecht Direct current electroluminescent devices
US4188565A (en) * 1977-09-16 1980-02-12 Sharp Kabushiki Kaisha Oxygen atom containing film for a thin-film electroluminescent element
EP0044686A1 (en) * 1980-07-17 1982-01-27 EASTMAN KODAK COMPANY (a New Jersey corporation) Organic electroluminescent cell, process for manufacturing the cell and its use
US4394601A (en) * 1973-07-05 1983-07-19 Sharp Kabushiki Kaisha ZnS:Mn Thin-film electroluminescent element with memory function
US4668582A (en) * 1984-03-23 1987-05-26 Matsushita Electric Industrial Co., Ltd. Thin film EL panel
US4670355A (en) * 1984-02-29 1987-06-02 Hoya Corporation Electroluminescent panel comprising a dielectric layer of a mixture of tantalum oxide and aluminum oxide
US4717859A (en) * 1984-12-14 1988-01-05 Gold Star Co., Ltd. Polychromatic electro luminescence display device
EP0258888A2 (en) * 1986-09-05 1988-03-09 Matsushita Electric Industrial Co., Ltd. Thin film electroluminescence display device
US4734618A (en) * 1985-01-31 1988-03-29 Hoya Corporation Electroluminescent panel comprising a layer of silicon between a transparent electrode and a dielectric layer and a method of making the same
US4849674A (en) * 1987-03-12 1989-07-18 The Cherry Corporation Electroluminescent display with interlayer for improved forming
US4859904A (en) * 1985-06-04 1989-08-22 Phosphor Products Company Limited High contrast electroluminescent displays
US4900584A (en) * 1987-01-12 1990-02-13 Planar Systems, Inc. Rapid thermal annealing of TFEL panels
EP0388608A1 (en) * 1989-03-24 1990-09-26 Matsushita Electric Industrial Co., Ltd. Thin-film electroluminescence apparatus
US5003221A (en) * 1987-08-29 1991-03-26 Hoya Corporation Electroluminescence element
US5004956A (en) * 1988-08-23 1991-04-02 Westinghouse Electric Corp. Thin film electroluminescent edge emitter structure on a silcon substrate
US5043631A (en) * 1988-08-23 1991-08-27 Westinghouse Electric Corp. Thin film electroluminescent edge emitter structure on a silicon substrate
EP0507447A2 (en) * 1991-03-06 1992-10-07 The Boeing Company High luminance and contrast flat display panel
WO1999049989A1 (en) * 1998-03-27 1999-10-07 The Ohio State University Voltage controlled color variable light-emitting devices featuring multilayers of discrete polymer layers and molecular/oligomer layers
US6133933A (en) * 1997-01-13 2000-10-17 Xerox Corporation Color Xerographic printing system with multicolor printbar
GB2349979A (en) * 1999-05-10 2000-11-15 Cambridge Display Tech Ltd Light-emitting devices
CN103921582A (en) * 2014-02-24 2014-07-16 苏州大学 Variable color thermoprinting membrane and making method thereof

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887402A (en) * 1958-05-29 1959-05-19 Du Pont Method of producing electroluminescent lamps
US3046432A (en) * 1960-10-19 1962-07-24 Jr Richard B Nehrich Electroluminescent light
US3175116A (en) * 1962-05-02 1965-03-23 Canrad Prec Ind Inc Electroluminescent condenser
US3248669A (en) * 1962-10-30 1966-04-26 Ibm Semiconductor laser with optical cavity
US3268755A (en) * 1961-03-30 1966-08-23 Optische Ind De Oude Delft Nv Current-electroluminescence device having a high resistance layer
US3560784A (en) * 1968-07-26 1971-02-02 Sigmatron Inc Dark field, high contrast light emitting display
US3576356A (en) * 1969-01-14 1971-04-27 Ibm Antiglare coating for cathode-ray tube used with capacitive coupled voltage pen

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887402A (en) * 1958-05-29 1959-05-19 Du Pont Method of producing electroluminescent lamps
US3046432A (en) * 1960-10-19 1962-07-24 Jr Richard B Nehrich Electroluminescent light
US3268755A (en) * 1961-03-30 1966-08-23 Optische Ind De Oude Delft Nv Current-electroluminescence device having a high resistance layer
US3175116A (en) * 1962-05-02 1965-03-23 Canrad Prec Ind Inc Electroluminescent condenser
US3248669A (en) * 1962-10-30 1966-04-26 Ibm Semiconductor laser with optical cavity
US3560784A (en) * 1968-07-26 1971-02-02 Sigmatron Inc Dark field, high contrast light emitting display
US3576356A (en) * 1969-01-14 1971-04-27 Ibm Antiglare coating for cathode-ray tube used with capacitive coupled voltage pen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Electroluminescence and Semiconductor Lasers, by Henry F. Ivey, IEEE Journal of Quantum Electronics, Vol. QE 2, No. 11, November 1966, pages 713 726. *

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4394601A (en) * 1973-07-05 1983-07-19 Sharp Kabushiki Kaisha ZnS:Mn Thin-film electroluminescent element with memory function
US4140937A (en) * 1975-07-22 1979-02-20 Aron Vecht Direct current electroluminescent devices
US4137481A (en) * 1976-10-29 1979-01-30 The Secretary Of State Of Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Electroluminescent phosphor panel
FR2369640A1 (en) * 1976-10-29 1978-05-26 Secr Defence Brit ELECTROLUMINESCENT PANELS
US4188565A (en) * 1977-09-16 1980-02-12 Sharp Kabushiki Kaisha Oxygen atom containing film for a thin-film electroluminescent element
EP0044686A1 (en) * 1980-07-17 1982-01-27 EASTMAN KODAK COMPANY (a New Jersey corporation) Organic electroluminescent cell, process for manufacturing the cell and its use
US4670355A (en) * 1984-02-29 1987-06-02 Hoya Corporation Electroluminescent panel comprising a dielectric layer of a mixture of tantalum oxide and aluminum oxide
US4668582A (en) * 1984-03-23 1987-05-26 Matsushita Electric Industrial Co., Ltd. Thin film EL panel
US4717859A (en) * 1984-12-14 1988-01-05 Gold Star Co., Ltd. Polychromatic electro luminescence display device
US4734618A (en) * 1985-01-31 1988-03-29 Hoya Corporation Electroluminescent panel comprising a layer of silicon between a transparent electrode and a dielectric layer and a method of making the same
US4859904A (en) * 1985-06-04 1989-08-22 Phosphor Products Company Limited High contrast electroluminescent displays
US4869973A (en) * 1986-09-05 1989-09-26 Matsushita Electric Industrial Co., Ltd. Thin film electroluminescence display device
EP0258888A3 (en) * 1986-09-05 1988-06-22 Matsushita Electric Industrial Co., Ltd. Thin film electroluminescence display device
EP0258888A2 (en) * 1986-09-05 1988-03-09 Matsushita Electric Industrial Co., Ltd. Thin film electroluminescence display device
US4900584A (en) * 1987-01-12 1990-02-13 Planar Systems, Inc. Rapid thermal annealing of TFEL panels
US4849674A (en) * 1987-03-12 1989-07-18 The Cherry Corporation Electroluminescent display with interlayer for improved forming
US5003221A (en) * 1987-08-29 1991-03-26 Hoya Corporation Electroluminescence element
US5004956A (en) * 1988-08-23 1991-04-02 Westinghouse Electric Corp. Thin film electroluminescent edge emitter structure on a silcon substrate
US5043631A (en) * 1988-08-23 1991-08-27 Westinghouse Electric Corp. Thin film electroluminescent edge emitter structure on a silicon substrate
EP0388608A1 (en) * 1989-03-24 1990-09-26 Matsushita Electric Industrial Co., Ltd. Thin-film electroluminescence apparatus
US4995043A (en) * 1989-03-24 1991-02-19 Matsushita Electric Industrial Co., Ltd. Thin-film electroluminescence apparatus including optical interference filter
EP0615402A2 (en) * 1989-03-24 1994-09-14 Matsushita Electric Industrial Co., Ltd. Thin-film electroluminescence apparatus including optical interference filter
EP0615402A3 (en) * 1989-03-24 1994-10-19 Matsushita Electric Ind Co Ltd Thin-film electroluminescence apparatus including optical interference filter.
EP0507447A2 (en) * 1991-03-06 1992-10-07 The Boeing Company High luminance and contrast flat display panel
EP0507447A3 (en) * 1991-03-06 1993-09-22 The Boeing Company High luminance and contrast flat display panel
US6133933A (en) * 1997-01-13 2000-10-17 Xerox Corporation Color Xerographic printing system with multicolor printbar
WO1999049989A1 (en) * 1998-03-27 1999-10-07 The Ohio State University Voltage controlled color variable light-emitting devices featuring multilayers of discrete polymer layers and molecular/oligomer layers
GB2349979A (en) * 1999-05-10 2000-11-15 Cambridge Display Tech Ltd Light-emitting devices
CN103921582A (en) * 2014-02-24 2014-07-16 苏州大学 Variable color thermoprinting membrane and making method thereof

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