OLEDs doped with phosphorescent compounds

• US 7,279,237 B2
• Filed: 08/23/2006
• Issued: 10/09/2007
• Est. Priority Date: 12/01/1997
• Status: Expired due to Fees

• Current Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Original Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Inventors: Burrows, Paul E., Forrest, Stephen R., Sibley, Scott, Thompson, Mark E., You, Yujian, Shoustikov, Andrei
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US11/509,452
• Publication Number:
  US 20060286409A1
• Time in Patent Office: 412 Days
• Field of Search: None
• US Class Current: 428/690
• CPC Class Codes: C07D 487/22 in which the condensed system contains four or more hetero rings
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/10 Non-macromolecular compounds
• CPC Class Codes: C09K 2211/1003 Carbocyclic compounds
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1018 Heterocyclic compounds
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/1074 containing more than three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/18 Metal complexes
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: C09K 2211/186 of the light metals other than alkali metals and alkaline earth metals, i.e. Be, Al or Mg
• 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: H05B 33/28 of translucent electrodes
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/80524 : Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 85/30 : Coordination compounds
• CPC Class Codes: H10K 85/324 : comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/341 : Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/346 : comprising platinum
• CPC Class Codes: H10K 85/621 : Aromatic anhydride or imide compounds, e.g. perylene tetra-carboxylic dianhydride or perylene tetracarboxylic di-imide
• CPC Class Codes: H10K 85/654 : comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: Y10S 428/917 : Electroluminescent
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree

Abstract

Organic light emitting devices are disclosed, which comprise a heterostructure for producing electroluminescence, wherein the heterostructure comprises an emissive layer containing a phosphorescent dopant compound. For example, the phosphorescent dopant compound may comprise platinum octaethylporphine (PtOEP), which is a compound having the chemical structure with the formula:

Claims

1. An organic light emitting device, comprising an emissive layer that comprises a phosphorescent material and a charge carrying host material, wherein the phosphorescent material is capable of a photoluminescent quantum yield greater than 50 percent in the solid state at room temperature, and the phosphorescent material emits phosphorescent radiation from a triplet molecular excited state when a voltage is applied across the organic light emitting device.

2. The device of claim 1, wherein the organic light emitting device is capable of a display brightness in excess of 10 cd/m².

3. The device of claim 1, wherein the charge carrying host material is a hole transporting material.

4. The device of claim 1, wherein the charge carrying host material is an electron transporting material.

5. The device of claim 1, wherein the phosphorescent material has a phosphorescent lifetime not longer than 10 microseconds.

6. The device of claim 1, wherein the phosphorescent material has a photoluminescent lifetime from 10 to 100 microseconds.

7. The device of claim 1, wherein the phosphorescent material has the chemical structure of formula I:

8. The device of claim 7, wherein the phosphorescent material is platinum octaethylporphine and has the chemical structure with the formula:

9. The device of claim 1, wherein the device is capable of an external quantum efficiency of from 0.07% to 0.14% at ambient environmental conditions when a voltage is applied across the organic light emitting device.

10. The device of claim 1, wherein the device is capable of an external quantum efficiency of from 0.07% to 0.14% at room temperature when a voltage is applied across the organic light emitting device.

11. A method for preparing an organic light emitting device, comprising positioning an emissive layer that produces electroluminescence between an anode and a cathode, wherein the emissive material is a phosphorescent material capable of a photoluminescent quantum yield greater than 50 percent in the solid state at room temperature.