OLED device with improved performance

• US 20060240278A1
• Filed: 04/20/2005
• Published: 10/26/2006
• Est. Priority Date: 04/20/2005
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Tyan, Yuan-Sheng, Hatwar, Tukaram K., Liao, Liang-Sheng, Van Slyke, Steven A.
• Granted Patent: US 8,057,916 B2
• Time in Patent Office: Days
• US Class Current: 428/690
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An OLED device includes an anode, a cathode, and at least one individually selected organic light-emitting layer disposed between the anode and cathode. The device also includes an electron-transporting layer disposed between the at least one light-emitting layer and the cathode, such electron-transporting layer including a first electron-transporting material, and an electron-injecting layer disposed between the electron-transporting layer and the cathode, such electron-injecting layer including a metal dopant having a work function less than 4.0 eV and an electron-transporting material that is different from the first electron-transporting material.

Claims

1. An OLED device, comprising:

a) an anode;

b) a cathode;

c) at least one individually selected organic light-emitting layer disposed between the anode and cathode;

d) an electron-transporting layer disposed between the at least one light-emitting layer and the cathode, such electron-transporting layer including a first electron-transporting material; and

e) an electron-injecting layer disposed between the electron-transporting layer and the cathode, such electron-injecting layer including a metal dopant having a work function less than 4.0 eV and an electron-transporting material that is different from the first electron-transporting material.

2. The OLED device of claim 1 wherein the low work function metal dopant is an alkali metal, an alkaline earth metal, or a rare earth metal, or combinations thereof.

3. The OLED device of claim 1 wherein the low work function metal dopant has a lower diffusivity in the first electron-transporting material than it has in the electron-transporting material of the electron-injecting layer.

4. The OLED device of claim 1 that produces broadband light.

5. The OLED device of claim 4 wherein the broadband light is white light having a chromaticity of CIE x=0.31±

0.05 and CIE y=0.33±

0.05.

6. The OLED device of claim 1 wherein the electron-transporting material of the electron-injecting layer includes one or more compounds selected from the group including metal chelated oxinoid compounds, butadiene derivatives, benzazole derivatives, oxadiazole derivatives, triazole derivatives, naphthacene derivatives, pyridinethiadiazole derivatives, triazine derivatives, silole derivatives, pyridine derivatives, and phenanthroline derivatives.

7. The OLED device of claim 1 wherein the organic light-emitting layer emits blue light and is provided adjacent to the first electron-transporting layer.

8. The OLED device of claim 1 wherein the electron-transporting material of the electron-injecting layer includes a mixture of electron-transporting compounds.

9. The OLED device of claim 8 wherein one of the compounds of the mixture of electron-transporting compounds is also used in the first electron-transporting layer.

10. The OLED device of claim 1 wherein the first electron-transporting layer includes a metal oxinoid derivative and the electron-injecting layer includes a phenanthroline derivative.

11. The OLED device of claim 1 further including a hole-injecting layer provided adjacent to the anode.

12. The OLED device of claim 11 wherein the hole-injecting layer includes a hole-transporting material and a p-type dopant.

13. The OLED device of claim 11 wherein the hole-injecting layer includes a material having a reduction potential greater than −

0.5 V vs. a Saturated Calomel Electrode.

14. The OLED device of claim 1 wherein the first electron-transporting material contains an oxygen atom.

15. The OLED device of claim 1 wherein the first electron-transporting material has a LUMO between that of the LUMO of the light-emitting layer and the electron-transporting material of the electron-injecting layer.

16. The OLED device of claim 1 wherein the first electron-transporting material is a metal oxinoid compound.

17. The OLED device of claim 1 wherein the first electron-transporting material includes a triazine compound.