Phosphorescent OLEDs with exciton blocking layer

• US 7,597,967 B2
• Filed: 12/17/2004
• Issued: 10/06/2009
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Brown, Christopher T., Kondakova, Marina E., Klubek, Kevin P., Huo, Shouquan, Deaton, Joseph C.
• Primary Examiner(s): GARRETT, DAWN L
• Application Number:
  US11/016,108
• Publication Number:
  US 20060134460A1
• Time in Patent Office: 1,754 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1022 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1059 containing three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1074 containing more than three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1077 with oxygen
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• 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: H10K 85/346 comprising platinum
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/656 comprising two or more different heteroatoms per ring H10K85/652 takes precedence
• CPC Class Codes: H10K 85/6565 Oxadiazole compounds
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An electroluminescent device comprises a cathode and an anode; and, located therebetween, a light-emitting layer (LEL) comprising at least one hole transporting co-host and at least one electron transporting co-host, together with at least one phosphorescent emitter, and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter, and further containing an exciton blocking layer comprising a hole transporting material with triplet energy greater or equal to 2.5 eV adjacent the emitting layer on the anode side. The invention provides devices that emit light with high luminous efficiency at low voltage.

Claims

1. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

a phosphorescent compound of Ir or Pt represented by the formula;

2. A device of claim 1 wherein the electron transporting co-host is selected from one of the formulae:

3. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

a phosphorescent compound of Ir or Pt represented by the formula;

4. A device of claim 3 wherein the electron transporting co-host is selected from the following formulae:

5. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

a phosphorescent compound of Ir or Pt represented by the formula;

6. A device of claim 5 wherein the electron transporting co-host is selected from one of the formulae:

7. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

a phosphorescent compound of Ir or Pt represented b the formula;

8. A device of claim 7 wherein the electron transporting co-host is a substituted or unsubstituted triazole having the formula:

9. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

a phosphorescent compound of Ir or Pt represented by the formula;

10. A device of claim 9 wherein the electron transporting co-host is selected from the group consisting of:

2,4,6-tris(diphenylamino)-1,3,5-triazine;

2,4,6-tricarbazolo-1,3,5-triazine;

2,4,6-tris(N-phenyl-2-naphthylamino)-1,3,5-triazine;

2,4,6-tris(N-phenyl-1-naphthylamino)-1,3,5-triazine;

4,4′

, 6,6′

-tetraphenyl-2,2′

-bi-1,3,5-triazine; and

2,4,6-tris([1,1′

;

3′

,1″

-terphenyl]-5′

-yl)-1,3,5-triazine.

11. An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising a phosphorescent compound of Ir or Pt represented by the formula: