OLED devices with dinuclear copper compounds

1. An OLED device comprising an anode, a cathode and therebetween a light emitting layer containing a phosphorescent compound represented by Formula I below:

wherein:

each A is independently selected from N and P;

each E is independently selected from N, P, and As;

each Z is a radical independently selected from the group consisting of

each R is an independently selected substituent; and

each R′ is independently selected from H and a substituent;

provided that two substituent groups can join to form a ring.

2. An OLED device of claim 1 wherein A represents N.

3. An OLED device of claim 2 wherein E represents P or As.

4. An OLED device of claim 1 wherein the compound is represented by Formula II below:

wherein:

each E′ is independently selected from P and As;

each R′ is independently selected from H and a substituent; and

each R 2 is independently selected from alkyl, aryl, heteroaryl and cyano substituents;

provided two substituent groups can join to form a ring.

5. An OLED device of claim 4 wherein E′ represents P.

6. An OLED device of claim 4 wherein the compound is represented by Formula III below:

wherein:

each E′ is independently selected from P and As;

each R is an independently selected substituent; and

each R′ is independently selected from H or a substituent;

provided two substituent groups can join to form a ring.

7. An OLED device of claim 6 wherein, R is selected from alkyl, aryl, heteroaryl, and CN.

8. An OLED device of claim 6 wherein adjacent R′ substituents join to form an aromatic ring.

9. An OLED device of claim 6 wherein E′ represents P.

10. An OLED device of claim 6 wherein, R is selected from isobutyl and phenyl.

11. An OLED device of claim 1 wherein, the compound is represented by Formula IV below:

wherein:

each E′ is independently selected from P and As;

each R is an independently selected substituent;

each R′ is independently selected from H and a substituent;

each R 2 is independently selected from alkyl, aryl, heteroaryl and cyano substituents; and

provided two substituent groups on adjacent atoms can join to form a ring.

12. An OLED device of claim 11 wherein E′ represents P.

13. An OLED device of claim 1 wherein the light emitting layer additionally comprises a carbazole.

14. An OLED device of claim 13 wherein the light emitting layer additionally comprises a compound selected from the group consisting of 4,4′-N,N′-dicarbazole-biphenyl (CBP), 9,9′-(1,3-phenylene)bis-9H-carbazole (mCP), 9,9′-(2,2′-dimethyl[1,1′-biphenyl]-4,4′-diyl)bis-9H-carbazole (CDBP), and 4-(9H-carbazol-9-yl)-N,N-bis[4-(9H-carbazol-9-yl)phenyl]-benzenamine (TCTA).

15. An OLED device of claim 1 wherein, the compound is from 1 to 15 wt % of the light emitting layer.

16. An OLED device of claim 1 including an exciton blocking layer adjacent to a phosphorescent light emitting layer, containing the phosphorescent compound of Formula (I) and a host material, on the anode side, and a hole-transporting layer adjacent to the exciton blocking layer on the anode side, the exciton blocking layer comprising a material having a triplet energy that exceeds that of the phosphorescent compound and is greater than 2.5 eV.

17. An OLED device of claim 16 wherein the material of said exciton blocking layer further comprises a material having a LUMO energy level greater by 0.2 eV or more than that of the host material of the light emitting layer.

18. An OLED device of claim 16 wherein the material in the exciton blocking layer is a triarylamine.

19. An OLED device of claim 18 wherein the triarylamine is selected from 1,1-Bis(4-(N,N-di-p-tolylamino)phenyl)cyclohexane and 2,2′-dimethyl-N,N,N′,N′-tetrakis(4-methylphenyl)-1,1′-biphenyl-4,4′-diamine.

20. An OLED device of claim 16 wherein the host material of the light emitting layer is a carbazole.

21. An OLED device of claim 20 wherein the host material is selected from the group consisting of 9,9′-(2,2′-dimethyl[1,1′-biphenyl]-4,4′-diyl)bis-9H-carbazole; 9,9′-(1,3-phenylene)bis-9H-carbazole; and 4-(9H-carbazol-9-yl)-N,N-bis[4-(9H-carbazol-9-yl)phenyl]-benzenamine.