OLEDs doped with phosphorescent compounds

• US 6,579,632 B2
• Filed: 07/06/2001
• Issued: 06/17/2003
• Est. Priority Date: 12/01/1997
• Status: Expired due to Term

• 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: Sibley, Scott, You, Yujian, Shoustikov, Andrei, Burrows, Paul E., Forrest, Stephen R., Thompson, Mark E.
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US09/900,650
• Publication Number:
  US 20010053463A1
• Time in Patent Office: 711 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 257/102
• 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 are comprised of a heterostructure for producing electroluminescence wherein the heterostructure is comprised of an emissive layer containing a phosphorescent dopant compound. For example, the phosphorescent dopant compound may be comprised of platinum octaethylporphine (PtOEP), which is a compound having the chemical structure with the formula:

Claims

1. An organic light emitting device for producing electroluminescence comprising:

an anode;

a hole transporting layer;

an electron transporting layer; and

a cathode;

wherein the hole transporting layer or the electron transporting layer is an emissive layer, the emissive layer comprises a phosphorescent material and a charge-carrying host material, wherein the phosphorescent material emits phosphorescent radiation from a triplet molecular excited state when a voltage is applied across the organic light emitting device, and wherein the organic light emitting device is capable of a display brightness in excess of 10 cd/m².

2. The organic light emitting device of claim 1, wherein the organic light emitting device is capable of a display brightness in excess of 100 cd/m².

3. The organic light emitting device of claim 1, wherein the hole transporting layer is the emissive layer.

4. The organic light emitting device of claim 1, wherein the electron transporting layer is the emissive layer.

5. The organic light emitting device of claim 1, wherein the phosphorescent material is present in a lower concentration than the charge carrying host material.

6. The organic light emitting device of claim 1, wherein the phosphorescent material has a phosphorescent lifetime not longer than about 10 milliseconds.

7. The organic light emitting device of claim 6, wherein the phosphorescent material has a phosphorescent lifetime not longer than about 10 microseconds.

8. The organic light emitting device of claim 1, wherein the phosphorescent material has the chemical structure of formula I:

wherein X is C or N;

R₈, R₉ and R₁₀ are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl and substituted aryl;

R₉ and R₁₀ may be combined together to form a fused ring;

M₁ is a divalent, trivalent or tetravalent metal; and

a, b and c are each 0 or 1;

wherein, when X is C, then a is 1;

when X is N, then a is 0;

when c is 1, then b is 0; and

when b is 1, c is 0.

9. The organic light emitting device of claim 8, wherein M₁ is Pt.

10. An organic light emitting device for producing electroluminescence comprising:

an anode;

a hole transporting layer;

an emissive layer;

an electron transporting layer; and

a cathode;

wherein the emissive layer comprises a phosphorescent material and a charge-carrying host material, wherein the phosphorescent material emits phosphorescent radiation from a triplet molecular excited state when a voltage is applied across the organic light emitting device, and wherein the organic light emitting device is capable of a display brightness in excess of 10 cd/m².

11. The organic light emitting device of claim 10, wherein the organic light emitting device is capable of a display brightness in excess of 100 cd/m².

12. The organic light emitting device of claim 10, wherein the phosphorescent material is present in a lower concentration than the charge carrying host material.

13. The organic light emitting device of claim 10, wherein the phosphorescent material has a phosphorescent lifetime not longer than about 10 milliseconds.

14. The organic light emitting device of claim 13, wherein the phosphorescent material has a phosphorescent lifetime not longer than about 10 microseconds.

15. The organic light emitting device of claim 10, wherein the phosphorescent material has the chemical structure of formula I:

wherein X is C or N;

R₈, R₉ and R₁₀ are each independently selected from the group consiting of hydrogen, alkyl, substituted alkyl, aryl and substituted aryl;

R₉ and R₁₀ may be combined together to form a fused ring;

M₁ is a divalent, trivalent or tetravalent metal; and

a, b and c are each 0 or 1;

wherein, when X is C, then a is 1;

when X is N, then a is 0;

when c is 1, then b is 0; and

when b is 1, c is 0.

16. The organic light emitting device of claim 15, wherein M₁ is Pt.