White organic light emitting device

• US 7,968,214 B2
• Filed: 11/28/2007
• Issued: 06/28/2011
• Est. Priority Date: 01/12/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Euk-che, Tamura, Shinichiro, Kido, Junji, Noh, Tae-yong
• Primary Examiner(s): Garrett; Dawn L
• Application Number:
  US11/946,275
• Publication Number:
  US 20080171226A1
• Time in Patent Office: 1,308 Days
• Field of Search: None
• US Class Current: 428/690
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

Provided is a white organic light emitting device comprising an anode, a cathode, and an organic layer formed between the anode and the cathode, wherein the organic layer comprises one green emissive layer, one blue emissive layer, one red emissive layer, and one charge generating layer formed between any two of the foregoing green, blue and red emissive layers. The white organic light emitting device has a tandem structure providing the simplest structure for the three color light emissions of green, blue and red.

Claims

1. A white organic light emitting device comprising:

an anode,

a cathode, and

an organic layer formed between the anode and the cathode, wherein the organic layer comprises one green emissive layer, one blue emissive layer, one red emissive layer, and only one charge generating layer formed between any two of the foregoing green, blue and red emissive layers,

wherein the charge generating layer comprises a charge generating compound selected from a metal, metal oxides, metal carbides, metal fluorides, or a combination comprising at least one of the foregoing charge generating compounds, and

the charge generating layer contacts at least one of the green emissive layer, the blue emissive layer, and the red emissive layer.

2. The white organic light emitting device of claim 1, wherein the metal is selected from Cs, Mo, V, Ti, W, Ba or Li, or a combination comprising at least one of the foregoing metals.

3. The white organic light emitting device of claim 1, wherein the metal oxides, metal carbides and metal fluorides are selected from Re₂O₇, MoO₃, V₂O₅, WO₃, TiO₂, Cs₂CO₃, BaF, LiF, or CsF, or a combination comprising at least one of the foregoing metal oxides, metal carbides and metal fluorides.

4. The white organic light emitting device of claim 1, wherein the green emissive layer, the blue emissive layer and the red emissive layer each comprise a host material, and a fluorescent or phosphorescent light emitting material as a dopant.

5. The white organic light emitting device of claim 1, wherein the emissive layers of the organic layer are formed from the anode side in the order of the green emissive layer, the blue emissive layer and the red emissive layer.

6. The white organic light emitting device of claim 5, wherein a charge generating layer is formed between the green emissive layer and the blue emissive layer.

7. The white organic light emitting device of claim 1, wherein the emissive layers of the organic layer are formed from the anode side in the order of the blue emissive layer, the green emissive layer and the red emissive layer.

8. The white organic light emitting device of claim 7, wherein a charge generating layer is formed between the blue emissive layer and the green emissive layer.

9. The white organic light emitting device of claim 4, wherein the green emissive layer comprises Alq₃ as the host material and coumarin as the dopant.

10. The white organic light emitting device of claim 4, wherein the blue emissive layer comprises 2-tert-butyl-9,10-bis-(β

-naphthyl)-anthracene as the host material and 4,4′

-bis(2,2-diphenylvinyl)biphenyl as the dopant.

11. The white organic light emitting device of claim 4, wherein the red emissive layer comprises Alq₃ as the host material and 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran as the dopant.

12. The white organic light emitting device of claim 1, wherein the organic layer further comprises at least one layer selected from a hole injection layer, an electron blocking layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer or an electron injection layer, or a combination comprising at least one of the foregoing layers.