Organic light emitting diodes for production of polarized light

• US 7,037,599 B2
• Filed: 02/28/2003
• Issued: 05/02/2006
• Est. Priority Date: 02/28/2003
• Status: Expired due to Term

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.), University of Rochester
• Original Assignee: Eastman Kodak Company
• Inventors: Tang, Ching W., Vaeth, Kathleen M., Klubek, Kevin P., Geng, Yanhou, Culligan, Sean W., Chen, Shaw H.
• Primary Examiner(s): Dye, Rena
• Assistant Examiner(s): Thompson, Camie S.
• Application Number:
  US10/377,046
• Publication Number:
  US 20040170861A1
• Time in Patent Office: 1,159 Days
• Field of Search: 313/503, 313/504, 313/506, 428/690, 428/917, 252/301.16
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 19/32 containing condensed ring systems, i.e. fused, bridged or spiro ring systems
• CPC Class Codes: C09K 2211/1416 Condensed systems
• CPC Class Codes: C09K 2211/1466 containing nitrogen as the only heteroatom
• CPC Class Codes: C09K 2211/1475 containing nitrogen and oxygen as heteroatoms
• CPC Class Codes: C09K 2211/1483 containing nitrogen and sulfur as heteroatoms
• 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 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/868 Arrangements for polarized light emission H10K50/86 takes precedence
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/115 Polyfluorene; Derivatives thereof
• CPC Class Codes: H10K 85/151 Copolymers
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An OLED device comprising a substrate, an anode electrode and a cathode electrode, a uniaxial alignment layer disposed between the anode electrode and the cathode electrode, a light-emitting layer disposed over the uniaxial alignment layer and capable of producing polarized light, and a carrier confinement layer disposed over the light emitting layer and wherein the carrier confinement layer blocks either holes, electrons, or excitons. The light-emitting layer includes an oligomeric fluorene or a mixture of oligomeric fluorenes.

Claims

1. An OLED device comprising a substrate, an anode electrode and a cathode electrode, a uniaxial alignment layer disposed between the anode electrode and the cathode electrode, a light-emitting layer disposed over the uniaxial alignment layer and capable of producing polarized light, wherein the molecules in the light-emitting layer must be aligned uniaxially along a specific direction and a carrier confinement layer disposed over the light emitting layer and wherein the carrier confinement layer blocks either holes, electrons, or excitons, and wherein recombination of holes from the anode and electrons from the cathode is confined to this layer.

2. An OLED device according to claim 1 wherein the light-emitting layer contains an oligomeric fluorene or a mixture of oligomeric fluorenes.

3. The OLED device according to claim 2 wherein the fluorene or mixture of oligomeric fluorenes includes:

wherein;

R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈ are each individually alkyl of from 1 to 20 carbon atoms, which are branched or unbranched, aryl or substituted aryl of from 5 to 24 carbon atoms, heteroaryl or substituted heteroaryl of from 5 to 24 carbon atoms, alkoxy, aryloxy, alkyl ether or aryl ether;

m+n is in the range of 1 to 20;

x+y is in the range of 1 to 20;

EG₁ and EG₂ are hydrogen, alkyl of from 1 to 20 carbon atoms, which are branched or unbranched, phenyl or substituted phenyl;

and Ar is;

wherein;

p is in a range of from 1 to 10;

R is alkyl of from 1 to 20 carbon atoms, which are branched or unbranched, aryl or substituted aryl of from 5 to 24 carbon atoms, heteroaryl or substituted heteroaryl of from 5 to 24 carbon atoms, alkoxy, aryloxy, alkyl ether or aryl ether,

or,

wherein;

p is in the range of from 1 to 10;

R₉, R₁₀, R₁₁, R₁₂, R₁₃, and R₁₄ are each individually hydrogen, alkyl of from 1 to 20 carbon atoms, which are branched or unbranched, aryl or substituted aryl of from 5 to 24 carbon atoms, heteroaryl or substituted heteroaryl of from 5 to 24 carbon atoms, alkoxy, aryloxy, alkyl ether or aryl ether;

and X, Y, and Z are individually oxygen, sulfur, or nitrogen,

or,

wherein;

R15, R16, R19, and R20 are each individually hydrogen or cyano;

R17, R18, are hydrogen, cyano, alkoxy, alkyl of from 1 to 20 carbon atoms, aryl or substituted aryl of from 5 to 24 carbon atoms.

4. An OLED device according to claim 1 wherein the electroluminescence generated from the device is polarized light with a dichroic ratio greater than 10.

5. An OLED device according to claim 1 wherein the uniaxial alignment layer is disposed on the light-emitting layer.

6. An OLED device according to claim 1 wherein the light emitting layer is disposed between the uniaxial alignment layer and the carrier confinement layer.

7. An OLED device according to claim 1 wherein the uniaxial alignment layer is a rubbed polymer thin film.

8. An OLED device according to claim 1 wherein the uniaxial alignment layer is a vapor-deposited thin film.

9. An OLED device according to claim 1 wherein the uniaxial alignment layer is a photo-crosslinked polymer.

10. An OLED device according to claim 1 wherein the carrier confinement layer transports electrons and blocks holes.

11. An OLED device according to claim 1 wherein the carrier confinement layer transports holes and blocks electrons.

12. An OLED device according to claim 1 wherein the carrier confinement layer blocks excitons generated in the light-emitting layer.

13. An OLED device according to claim 1 wherein the ionization potential of the carrier confinement layer is greater than that of the light-emitting layer.

14. An OLED device according to claim 1 wherein the ionization potential of the carrier confinement layer is greater than 5.5 eV.

15. An OLED device according to claim 1 wherein the carrier confinement layer is comprised of organic compounds each with an ionization potential greater than 5.5 eV.

16. An OLED device according to claim 1 wherein the light-emitting layer contains a compound of the formula:

17. An OLED device according to claim 1 wherein the light-emitting layer contains a compound of the formula:

18. An OLED device according to claim 1 wherein the light-emitting layer contains a compound of the formula:

19. An OLED device according to claim 1 wherein the light emitting layer contains a compound of the formula: