ELECTROLUMINESCENT EFFICIENCY

• US 20100176390A1
• Filed: 03/16/2010
• Published: 07/15/2010
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: Bin Ma, David Knowles, Raymond Kwong, William Ceyrolles, Xiao-Chang Charles Li
• Original Assignee: Bin Ma, David Knowles, Raymond Kwong, William Ceyrolles, Xiao-Chang Charles Li
• Inventors: CEYROLLES, William, LI, Xiao-Chang Charles, KNOWLES, David, MA, Bin, KWONG, Raymond
• Granted Patent: US 8,449,990 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: C07F 15/0033 Iridium compounds
• CPC Class Codes: C07F 15/006 Palladium compounds
• CPC Class Codes: C07F 15/0073 Rhodium compounds
• CPC Class Codes: C07F 15/0086 Platinum compounds
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: C09K 2211/1092 containing sulfur as the only heteroatom
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An organic light emitting device is provided. The device has an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further includes a molecule of Formula I (shown below) wherein an alkyl substituent at position R′₅ results in high efficiency and operational stability in the organic light emitting device.

Claims

1. A compound having the formula:

wherein

M is a metal selected from Ir, Pt, Rh, or Pd;

(X-Y) is an ancillary ligand;

m is a value from 1 to the maximum number of ligands that may be attached to the metal;

and m+n is the maximum number of ligands that may be attached to the metal;

wherein R′

₅ is an unsubstituted alkyl having 1-15 carbon atoms;

wherein R′

₃ is an alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl, and is optionally substituted by one or more substituents Z;

wherein R′

₄ and R′

₆ are each independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl, and each is optionally substituted by one or more substituents Z;

wherein R₃, R₄, R₅, and R₆ are each independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CO₂R, C(O)R, NR₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

each R is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;

wherein R is optionally substituted by one or more substituents Z;

each Z is independently a halogen, R′

, OR′

, N(R′

)₂, SR′

, C(O)R′

, C(O)OR′

, C(O)N(R′

)₂, CN, SO₂, SOR′

, SO₂R′

, or SO₃R′

;

each R′

is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, or heteroaryl.

2. The compound of claim 1, wherein R′

₃ and R′

₄ on ring A together form a fused ring, wherein the fused ring is optionally substituted.

3. The compound of claim 1, wherein R′

₃ and R₆ are bridged by a group selected from;

—

CR₂—

CR₂—

, —

CR═

CR—

, —

CR₂, —

O—

, —

NR—

, —

O—

CR₂, —

NR—

CR₂, and —

N═

CR—

.

4. The compound of claim 2, wherein the compound is:

5. The compound of claim 3, wherein the compound is:

6. The compound of claim 1, wherein R₃, R₄, and R₅ are all H.

7. The compound of claim 1, wherein m=3, n=0, and M is iridium.

8. The compound of claim 1, wherein R′

₅ is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl.

9. A compound having the formula:

wherein

M is a metal selected from Ir, Pt, Rh, or Pd;

(X-Y) is an ancillary ligand;

m is a value from 1 to the maximum number of ligands that may be attached to the metal;

and m+n is the maximum number of ligands that may be attached to the metal;

wherein R′

₅ is an unsubstituted alkyl having 1-15 carbon atoms;

wherein R′

₃, R′

₄, and R′

₆ are each independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl, and each is optionally substituted by one or more substituents Z;

wherein R₃, R₅, and R₆ are each independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CO₂R, C(O)R, NR₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

wherein R₇ represents one or more optional substitutions located on any position of ring C, wherein the one or more optional R₇ substitutions are all fluoro or all alkyl;

each R is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;

wherein R is optionally substituted by one or more substituents Z;

each Z is independently a halogen, R′

, OR′

, N(R′

)₂, SR′

, C(O)R′

, C(O)OR′

, C(O)N(R′

)₂, CN, SO₂, SOR′

, SO₂R′

, or SO₃R′

;

each R′

is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, or heteroaryl.

10. The compound of claim 9, wherein ring C is a linking group covalently linking two or more of the ligands that are attached to the metal.

11. The compound of claim 10, wherein all the ligands in the compound are linked via ring C.

12. The compound of claim 11, wherein the compound has the structure:

13. The compound of claim 9, wherein m=3, n=0, and M is iridium.

14. An organic light emitting device comprising:

an anode;

a cathode;

an organic layer disposed between the anode and the cathode, wherein the organic layer comprises an emissive material;

wherein the device produces phosphorescent emission and has an unmodified external quantum efficiency of at least 10% when operated at a current density between 0.1 to 1000 mA/cm²;

wherein the emissive material has the formula;

wherein

M is a metal selected from Ir, Pt, Rh or Pd;

(X-Y) is an ancillary ligand;

m is a value from 1 to the maximum number of ligands that may be attached to the metal;

and m+n is the maximum number of ligands that may be attached to the metal;

wherein R′

₅ is an unsubstituted alkyl having 1-15 carbon atoms;

wherein R′

₃, R′

₄, and R′

₆ is each independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl, and each is optionally substituted by one or more substituents Z;

wherein R₃, R₄, R₅, and R₆ is each independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CO₂R, C(O)R, NR₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

each R is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;

wherein R is optionally substituted by one or more substituents Z;

each Z is independently a halogen, R′

, OR′

, N(R′

)₂, SR′

, C(O)R′

, C(O)OR′

, C(O)N(R′

)₂, CN, SO₂, SOR′

, SO₂R′

, or SO₃R′

;

each R′

is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, or heteroaryl.

15. The device of claim 14, wherein the device has an unmodified external quantum efficiency of at least 15% when operated at a current density between 0.1 to 1000 mA/cm².

16. The device of claim 14, wherein the organic layer is a first organic layer, and further comprising a second organic layer disposed between the first organic layer and the cathode, wherein the second organic layer is in direct contact with the first organic layer, and wherein the second organic layer comprises an non-heterocyclic aromatic hydrocarbon material.

17. The device of claim 16, wherein the aromatic hydrocarbon material has a molecular dipole moment less than about 2.0 debyes.

18. The device of claim 14, wherein the device has a T_(0.5)-L₀ product that is at least 3×

10⁶ nit-hours.

19. The device of claim 14, wherein the emissive material is selected from:

20. The device of claim 14, wherein the emissive material is: