Organic element for electroluminescent devices
View Patent ↗Disclosed is an electroluminescent device comprising a light-emitting layer containing a light emitting material that contains an organometallic complex comprising a metal selected from the group consisting of Pt, Pd and Ir, and a tridentate (N^C^N) ligand, wherein the tridentate (N^C^N) ligand represents a ligand that coordinates to the metal through a nitrogen donor bond, a carbon-metal bond, and a nitrogen donor bond, in that order, wherein at least one of the nitrogen donors is part of an aromatic ring or an imine group. The invention also includes a display or room lighting device employing the device of the invention and a process of emitting light from the device of the invention. The device of the invention provides good luminance efficiency.
1. An electroluminescent device comprising a light-emitting layer containing a light emitting material that contains an organometallic complex comprising a metal selected from the group consisting of Pt, Pd and Ir, and a tridentate (N^C^N) ligand, wherein the tridentate (N^C^N) ligand represents a ligand that coordinates to the metal through a nitrogen donor bond, a carbon-metal bond, and a nitrogen donor bond, in that order, wherein at least one of the nitrogen donors is part of an aromatic ring or an imine group.
2. The device of claim 1 wherein the metal is Pt.
3. The device of claim 1 wherein each of the nitrogen donors is part of an aromatic ring.
4. The device of claim 1 wherein the organometallic complex can be represented by Formula (1a),
wherein:
Ar a , Ar b , and Ar c independently represent the atoms necessary to form a five or six-membered aromatic ring group; and
L is an anionic ligand.
5. The device of claim 4 wherein Ar a , Ar b , and Ar c independently represent the atoms necessary to form a six-membered aromatic ring group.
6. The device of claim 4 wherein Ar a and Ar c independently represent the atoms necessary to form a pyridine ring group.
7. The device of claim 4 wherein Ar b represents the atoms necessary to form a benzene ring group.
8. The device of claim 4 wherein L represents halogen.
9. The device of claim 4 wherein L represents a substituent that forms a carbon-platinum bond.
10. The device of claim 4 wherein L represents an alkynyl group, an alkenyl group, an aryl group, or an alkyl group.
11. The device of claim 4 wherein L represents RX, wherein X represents a substituent that forms a bond to platinum and wherein X represents N, O, S, or Se, and R represents a substituent.
12. The device of claim 1 wherein the organometallic complex is represented by Formula (1b),
wherein,
Z 1 –X 11 represent hydrogen or independently selected substituent groups, provided that adjacent substituent groups can combine to form rings, and provided that Z 4 and Z 5 , and Z 7 and Z 8 can also combine to form rings; and
L represents an anionic ligand.
13. The device of claim 12 wherein L represents halogen, an alkynyl group, an alkenyl group, an aryl group, an alkyl group, or RX, wherein X represents a substituent that forms a bond to platinum and wherein X represents N, O, S, or Se, and R represents an aryl group, an alkyl group, a carbonyl group or a sulfonyl group.
14. The device of claim 1 wherein the organometallic complex can be represented by Formula (1c),
wherein,
Z 1 –Z 11 represent independently selected substituent groups, provided that adjacent substituent groups can combine to form rings, and provided that Z 4 and Z 5 , and Z 7 and Z 8 can also combine to form rings; and
R 1 –R 5 represent hydrogen or independently selected substituents, provided that adjacent substituent groups can combine to form rings.
15. The device of claim 14 wherein R 1 and R 2 of Formula (1c) combine to form a six-membered ring group.
16. The device of claim 14 , wherein R 1 of Formula (1c) is a 1–12 carbon alkyl group.
17. The device of claim 14 wherein R 1 and R 2 , of Formula (1c), combine to form a six-membered ring group.
18. The device of claim 14 , wherein R 3 and R 4 also combine to form a six-membered ring group.
19. The device of claim 14 , wherein R 1 and R 3 independently represent a 1–12 carbon alkyl group.
20. The device of claim 1 wherein the light-emitting material is disposed in a host material.
21. The device of claim 20 wherein the light emitting material is present in an amount of up to 50 wt % based on the host.
22. The device of claim 20 wherein the light emitting material is present in an amount of up to 15 wt % based on the host.
23. The device of claim 1 capable of emitting white light.
24. The device of claim 23 including a filtering means.
25. The device of claim 1 including a fluorescent light emitting material in addition to the organometallic complex light emitting material.
26. The device of claim 1 wherein the organometallic complex contains a quinolinyl or isoquinolinyl group.
27. A display comprising the OLED device of claim 1 .
28. An area lighting device comprising the OLED device of claim 1 .