Electroluminescent efficiency

• US 7,709,100 B2
• Filed: 12/21/2004
• Issued: 05/04/2010
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: Universal Display Corporation
• Inventors: Ma, Bin, Li, Xiao-Chang, Knowles, David, Kwong, Raymond, Ceyrolles, William
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US11/018,453
• Publication Number:
  US 20060008673A1
• Time in Patent Office: 1,960 Days
• Field of Search: None
• US Class Current: 428/690
• 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, which is an alkyl substituent, results in high efficiency and operational stability in the organic light emitting device.

Claims

1. A compound having the formula:

2. The compound of claim 1 wherein m=3.

3. The compound of claim 1 having the formula:

4. The compound of claim 1 wherein at least one of R′

₃, R′

₄, and R′

₆ is not H.

5. The compound of claim 4 wherein at least one of R′

₃, R′

₄, and R′

₆ is alkyl or phenyl.

6. The compound of claim 1 wherein R′

₃, R′

₄, R′

₆, R₃, R₄, and R₆ are all H.

7. A device comprising:

an anode;

a cathode;

a first organic layer including an emissive material disposed between the anode and the cathode, the emissive material comprising a compound as set forth in claim 1.

8. The device of claim 7 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 a non-heterocyclic aromatic hydrocarbon material.

9. The device of claim 7 wherein the device produces phosphorescent emission and has an unmodified external quantum efficiency in the range of 10% to 23% at current densities between about 0.1 to about 1000 mA/cm².

10. The device of claim 8, wherein the aromatic hydrocarbon material has a molecular dipole moment less than about 2.0 debyes.

11. The device of claim 7, wherein the device has a T_(0.5)-L₀ product that is at least 3×

10⁶ nit-hours.

12. The device of claim 7, wherein the emissive material has the structure: