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.
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
Claim 2
Dependent Claim
136 words
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
Claim 3
Dependent Claim
61 words
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.