ORGANIC ELECTROLUMINESCENCE DEVICE

• US 20100225229A1
• Filed: 02/25/2010
• Published: 09/09/2010
• Est. Priority Date: 03/05/2009
• Status: Active Grant

• Current Assignee: UDC Ireland Limited (Universal Display Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: HOSODA, Hidemasa, TANI, Takeharu
• Granted Patent: US 8,018,145 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 59/877 comprising scattering means

Abstract

The present invention provides an organic electroluminescence display device including an organic electroluminescence element which includes a transparent electrode, a counter electrode, and an organic compound layer provided between these electrodes, the organic compound layer including a light emitting layer, and a fine particle containing layer positioned in the optical path of light emitted from the light emitting layer, wherein the fine particle containing layer contains an organic resin material, a first fine particle, and a second fine particle having a weight average particle diameter greater than that of the first fine particle, wherein a refractive index n₁ of the organic resin material into which the first fine particle is added and an average refractive index n₂ of the organic compound layer satisfy a relationship |n₁−n₂|<0.25, and wherein the refractive index n₁ and a refractive index n₃ of the second fine particle satisfy a relationship n₃−n₁>0.2.

Claims

1. An organic electroluminescence display device comprising:

an organic electroluminescence element which comprises a transparent electrode, a counter electrode, and an organic compound layer provided between the transparent electrode and the counter electrode, the organic compound layer including a light emitting layer, and

a fine-particle-containing-layer positioned in the optical path of light emitted from the light emitting layer,

wherein the fine-particle-containing-layer contains an organic resin material, a first fine particle, and a second fine particle having a weight average particle diameter greater than that of the first fine particle,

wherein a refractive index n₁ of the organic resin material into which the first fine particle is added and an average refractive index n₂ of the organic compound layer satisfy a relationship |n₁−

n₂|<

0.25, and

wherein the refractive index n₁ of the organic resin material into which the first fine particle is added and a refractive index n₃ of the second fine particle satisfy a relationship n₃−

n₁>

0.2.

2. The organic electroluminescence display device according to claim 1, wherein the second particle is an inorganic fine particle.

3. The organic electroluminescence display device according to claim 2, wherein the inorganic fine particle contains at least one selected from TiO₂, ZnO, and ZrO₂.

4. The organic electroluminescence display device according to claim 1, wherein the fine particle containing layer has a thickness of less than 5 μ

m.

5. The organic electroluminescence display device according to claim 1, wherein the fine particles in the fine-particle-containing-layer are primary particles.

6. The organic electroluminescence display device according to claim 5, wherein the fine particles in the fine-particle-containing-layer are surface-treated with an organic material.

7. The organic electroluminescence display device according to claim 1, wherein the fine particle containing layer further contains a fine particle dispersant.

8. The organic electroluminescence display device according to claim 1, wherein the weight average particle diameter of the first fine particle is less than 50 nm, and the weight average particle diameter of the second fine particle is 50 nm to 5 μ

m.

9. The organic electroluminescence display device according to claim 1, wherein the organic resin material contains at least one selected from imide resins, acrylic resins, ether resins, and silane resins.