Phosphorescent OLED with interlayer

• US 8,021,763 B2
• Filed: 11/23/2005
• Issued: 09/20/2011
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Kanno, Hiroshi, Forrest, Stephen
• Primary Examiner(s): Shosho; Callie
• Assistant Examiner(s): Wilson; Michael H
• Application Number:
  US11/285,059
• Publication Number:
  US 20070116983A1
• Time in Patent Office: 2,127 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 257/40, 257/E51.044
• US Class Current: 428/690
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

The present invention relates to phosphorescent stacked OLEDs having an interlayer.

Claims

1. A device comprising:

an anode;

a cathode;

an interlayer comprising a metal oxide disposed between the anode and the cathode;

a first organic phosphorescent unit disposed between and electrically connected to the anode and the interlayer; and

a second organic phosphorescent unit disposed between and electrically connected to the interlayer and the cathode;

wherein each of the first and second phosphorescent units further comprises an organic emissive layer, the organic emissive layer comprising an organic host material and a first organic dopant material and a second organic dopant material, wherein the first organic dopant material has a LUMO of at least 0.3 eV lower than the LUMO of the organic host material;

wherein each of the first and second organic phosphorescent units further comprises an exciton blocking layer; and

wherein the device emits white light with a CIE in the range of (0.33±

0.20, 0.33±

0.20) and a CRI of at least 60.

2. The device of claim 1, wherein the organic host material has a HOMO at least 0.3 eV lower than the HOMO of an adjacent layer, a LUMO at least 0.3 eV higher than the LUMO of an adjacent layer, or both.

3. The device of claim 1 wherein:

the anode comprises ITO;

the cathode comprises Al;

the interlayer comprises MoO₃; and

the emissive layer comprise mCP, CBP, or both.

4. The device of claim 1, wherein the interlayer is a first interlayer, and further comprising:

a second interlayer disposed between the first interlayer and the cathode; and

a third organic phosphorescent unit disposed between and electrically connected to the first interlayer and the second interlayer;

wherein the second organic phosphorescent unit is disposed between and electrically connected to the second interlayer and the cathode.

5. The device of claim 1 wherein the metal oxide is V₂O₅, indium tin oxide, RuO₂, TiO₂ or SnO₂.

6. The device of claim 1 wherein the metal oxide is MoO₃.

7. The device of claim 1 wherein the device has an efficiency of at least 10 lm/W.

8. The device of claim 1 wherein the device has an efficiency of at least 20 lmn/W.

9. The device of claim 1 wherein the device produces light with a brightness of at least 500 cd/m² lumens.

10. The device of claim 1 wherein the first organic dopant material has a HOMO at least 0.3 eV higher than the HOMO of the organic host material.

11. The device of claim 10 wherein:

the anode comprises ITO;

the cathode comprises Al;

the interlayer comprises MoO₃;

each of the organic host materials comprises mCP; and

each of the organic dopant materials comprises FlzIr.

12. The device of claim 10, wherein the organic host material has a HOMO at least 0.3 eV lower than the HOMO of a layer adjacent to the anode side of the phosphorescent unit.

13. The device of claim 12, wherein the layer adjacent to the anode side of the phosphorescent unit is a hole transport layer.

14. The device of claim 1, wherein the organic host material has a LUMO at least 0.3 eV higher than the LUMO of an adjacent layer.

15. The device of claim 14, wherein the adjacent layer is an electron transport layer.

16. The device of claim 1, wherein the organic host material is a first organic host material, and wherein the emissive layer in each of the first and second phosphorescent units further comprises a second organic host material.

17. The device of claim 16, wherein:

the anode comprises ITO;

the cathode comprises Al;

the interlayer comprises MoO₃;

each of the first organic host materials comprises mCP;

each of the second organic host materials comprises CBP;

each of the first organic dopant materials comprises FlzIr; and

each of the second organic dopant materials comprises Ir(ppy)₃, PQIr, or both.

18. The device of claim 1, wherein the device emits white light having a CRI of at least 75.

19. The device of claim 18, wherein the exciton blocking layer comprises Ir(ppz)₃.