Highly stable and efficient OLEDs with a phosphorescent-doped mixed layer architecture

• US 20020074935A1
• Filed: 12/15/2000
• Published: 06/20/2002
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Original Assignee: Universal Display Corporation
• Inventors: Brown, Julia J., Hack, Michael G., Ngo, Tan D., Kwong, Raymond C., Zhou, Theodore
• Granted Patent: US 6,803,720 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2101/90 Multiple hosts in the emissive layer
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/12 comprising dopants
• CPC Class Codes: H10K 85/311 Phthalocyanine
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine

Abstract

A highly stable and efficient organic light emitting device with a phosphorescent-doped mixed layer architecture comprises an anode layer; hole injecting layer over the anode layer; a mixed layer over the hole injecting layer, the mixed layer comprising an organic small molecule hole transporting material, an organic small molecule electron transporting material and a phosphorescent dopant; and a cathode layer over the mixed layer. An electron transporting layer may be present between the mixed layer and the cathode layer and a hole transporting layer may be present between the hole injecting layer and the mixed layer.

Claims

1. An organic light emitting device comprising:

a substrate;

an anode layer over the substrate;

a hole injecting layer over the anode layer;

a mixed layer over the hole injecting layer, the mixed layer functioning as an emission layer and comprising an organic small molecule hole transporting material, an organic small molecule electron transporting material and a phosphorescent dopant; and

a cathode layer over the mixed layer.

2. The device of claim 1, further comprising an electron transporting layer between the mixed layer and the cathode layer.

3. The device of claim 1, wherein the anode layer comprises indium tin oxide.

4. The device of claim 1, wherein the hole injecting layer comprises CuPc.

5. The device of claim 1, wherein the organic small molecule hole transporting material comprises NPD, the organic small molecule electron transporting material comprises Alq₃, and the phosphorescent dopant comprises PtOEP.

6. The device of claim 1, wherein the organic small molecule hole transporting material comprises NPD, the organic small molecule electron transporting material comprises Alq₃, and the phosphorescent dopant comprises BTPIr.

7. The device of claim 2, wherein the electron transporting layer comprises Alq₃.

8. The device of claim 1, wherein the cathode comprises magnesium-silver alloy.

9. The device of claim 1, wherein the cathode comprises LiF/Al.

10. The device of claim 1, wherein the substrate is transparent.

11. The device of claim 10, wherein the cathode layer is transparent.

12. The device of claim 10, wherein the substrate comprises plastic.

13. The device of claim 10, wherein the substrate comprises a flexible plastic.

14. The device of claim 1, wherein the substrate is substantially opaque and the cathode layer is transparent.

15. The device of claim 10, wherein the substrate comprises glass.

16. An electronic device incorporating the device of claim 1, the electronic device selected from the group consisting of a computer;

a television;

a large area wall, theater or stadium screen;

a billboard;

a sign;

a vehicle;

a printer;

a telecommunication device;

a telephone; and

a light source.

18. The device of claim 17, wherein the substrate is transparent.

19. The device of claim 17, wherein the substrate comprises glass.

20. The device of claim 17, wherein the substrate comprises plastic.

21. The device of claim 17, wherein the substrate comprises a flexible plastic.

24. The device of claim 2, further including an electron injection material between the electron transporting layer and the cathode.

17. An organic light emitting device comprising:

a substrate;

a substantially transparent anode layer comprising indium tin oxide;

a hole injecting layer over the anode layer, the hole injecting layer comprising CuPc;

a mixed layer over the hole injecting layer, the mixed layer functioning as an emission layer and comprising an organic small molecule hole transporting material, an organic small molecule electron transporting material and a phosphorescent dopant, the organic small molecule hole transporting material comprising NPD, the organic small molecule electron transporting material comprising Alq₃, and the phosphorescent dopant comprising PtOEP;

an electron transporting layer over the mixed layer, the electron transporting layer comprising Alq₃; and

a cathode layer over the electron transporting layer, the cathode layer comprising magnesium-silver alloy.

22. A multicolor display device comprising a plurality of pixels, wherein at least one of said pixels comprises:

a substrate;

substantially transparent anode layer over the substrate;

a hole injecting layer over the anode layer;

a mixed layer over the hole injecting layer, the mixed layer functioning as an emission layer and comprising an organic small molecule hole transporting material, an organic small molecule electron transporting material and a phosphorescent dopant;

an electron transporting layer over the mixed layer; and

a cathode layer over the electron transporting layer.

23. An electronic device incorporating the device of claim 22, the electronic device selected from the group consisting of a computer;

a television;

a large area wall, theater or stadium screen;

a billboard;

a sign;

a vehicle;

a printer;

a telecommunication device;

a telephone; and

a light source.

25. The device of claim 24, further including an exciton blocking layer between the hole injecting layer and the mixed layer.

26. The device of claim 25, wherein the exciton blocking layer is NPD.

27. The device of claim 24, wherein the electron injection material is LiF.

28. The device of claim 24, wherein the organic small molecule hole transporting material comprises NPD, the organic small molecule electron transporting material comprises Alq₃, and the phosphorescent dopant comprises BTPIr.

29. The device of claim 24, wherein the organic small molecule hole transporting material comprises NPD, the organic small molecule electron transporting material comprises Alq₃, and the phosphorescent dopant comprises PtOEP.

30. The device of claim 24, wherein the cathode layer comprises Al.