Phosphorescent OLED with interlayer

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 MoO 3 ; 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 V 2 O 5 , indium tin oxide, RuO 2 , TiO 2 or SnO 2 .

6. The device of claim 1 wherein the metal oxide is MoO 3 .

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/m 2 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 MoO 3 ;

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 MoO 3 ;

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 .