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US 7,888,700 B2Granted
Quantum dot light emitting device
AssigneeEastman Kodak Company
InventorKeith B. Kahen
Life of this patent
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Abstract
An inorganic light emitting device including a transparent substrate; a first electrode; a second electrode opposed to the first electrode; a polycrystalline inorganic light emitting layer including core/shell quantum dots within an inorganic semiconductor matrix and, wherein the first electrode is transparent and formed on the transparent substrate, the polycrystalline inorganic light emitting layer is formed over the first electrode, and the second electrode is formed over the light emitting layer.
Claims19
An inorganic light emitting device comprising:
- a transparent substrate;
- a first electrode;
- a second electrode opposed to the first electrode;
- a polycrystalline inorganic light emitting layer comprising core/shell quantum dots, without organic ligands, wherein the shells completely surround each of the cores of the core/shell quantum dots such that the shell that belongs to each core completely surrounds the core and wherein the core and shell materials are selected such that the valence and conduction band levels largely confine the core holes and electrons to the core region of the quantum dot and wherein each core/shell quantum dots is greater than 2 nanometers in diameter, within a conductive inorganic semiconductor matrix composed of fused inorganic nanoparticles, wherein the inorganic nanoparticles have a different composition from that of the core/shell quantum dots, are less than 2 nanometers in diameter, and there is at least a 2:1 ratio of inorganic nanoparticles to core/shell quantum dots, and, wherein the first electrode is transparent and formed on the transparent substrate, the polycrystalline inorganic light emitting layer is formed over the first electrode, and the second electrode is formed over the light emitting layer.
1 more element
An inorganic light emitting device comprising:
- a substrate;
- a first electrode;
- a second electrode opposed to the first electrode;
- a polycrystalline inorganic light emitting layer comprising core/shell quantum dots, wherein the shells completely surround each of the cores of the core/shell quantum dots such that the shell that belongs to each core completely surrounds the core and wherein the core and shell materials are selected such that the valence and conduction band levels largely confine the core holes and electrons to the core region of the quantum dot, and wherein each core/shell quantum dots is greater than 2 nanometers in diameter, without organic ligands, within a conductive inorganic semiconductor matrix composed of fused inorganic nanoparticles, wherein the inorganic nanoparticles have a different composition from that of the core/shell quantum dots, are less than 2 nanometers in diameter, and there is at least a 2:1 ratio of inorganic nanoparticles to core/shell quantum dots, and, wherein the first electrode is reflective and formed on the substrate, the polycrystalline inorganic light emitting layer is formed over the first electrode, and the second electrode is formed over the light emitting layer and is transparent.
1 more element
An inorganic light emitting device including a plurality of independently controlled light emitting elements, wherein at least one light emitting element comprises:
- a first patterned electrode;
- a second electrode opposed to the first electrode;
- and a polycrystalline inorganic light emitting layer comprising core/shell quantum dots, wherein the shells completely surround each of the cores of the core/shell quantum dots such that the shell that belongs to each core completely surrounds the core and wherein the core and shell materials are selected such that the valence and conduction band levels largely confine the core holes and electrons to the core region of the quantum dot, and wherein each core/shell quantum dots is greater than 2 nanometers in diameter, without organic ligands, within a conductive semiconductor matrix composed of fused inorganic nanoparticles, wherein the inorganic nanoparticles have a different composition from that of the core/shell quantum dots, are less than 2 nanometers in diameter, and there is at least a 2:1 ratio of inorganic nanoparticles to core/shell quantum dots, formed between the electrodes.
A method of making an inorganic light emitting device comprising:
- (a) providing a substrate;
- (b) forming a patterned first electrode on the substrate;
- (c) forming a polycrystalline inorganic light emitting layer comprising core/shell quantum dots, wherein the shells completely surround each of the cores of the core/shell quantum dots such that the shell that belongs to each core completely surrounds the core and wherein the core and shell materials are selected such that the valence and conduction band levels largely confine the core holes and electrons to the core region of the quantum dot, and wherein each core/shell quantum dots is greater than 2 nanometers in diameter, without organic ligands, within a conductive inorganic semiconductor matrix composed of fused inorganic nanoparticles, wherein the inorganic nanoparticles have a different composition from that of the core/shell quantum dots, are less than 2 nanometers in diameter., and there is at least a 2:1 ratio of inorganic nanoparticles to core/shell quantum dots, over the patterned first electrode;
- and
- (d) forming a second electrode opposed to the first electrode over the inorganic light emitting layer.
2 more elements
Dependencies are inferred from the claim text.