Organic light-emitting device incorporating a triplet-triplet annihilation promoter and method of forming the same

Patent metadata

Field	Value
Publication number	US-9548467-B2
Application number	US-201314398921-A
Country	US
Kind code	B2
Filing date	May 3, 2013
Priority date	May 4, 2012
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

Provided are organic light-emitting devices having an anode; a cathode; a first light-emitting layer between the anode and the cathode, the first light-emitting layer having a fluorescent light-emitting material with a triplet excited state energy level T 1F and a triplet-triplet annihilation (TTA) promoter with a triplet excited state energy level T 1T , wherein T 1F>1T ; and a second light-emitting layer between the anode and the cathode and adjacent to the first light-emitting layer, the second light-emitting layer having a phosphorescent material with a triplet excited state energy level T 1P , wherein T 1P >T 1T .

First claim

The invention claimed is:

1. An organic white light-emitting device comprising:
an anode;
a cathode;
a first light-emitting layer between the anode and the cathode, the first light-emitting layer comprising a fluorescent light-emitting material having a triplet excited state energy level T 1F and a triplet-triplet annihilation (TTA) promoter having a triplet excited state energy level T 1T wherein T 1F >T 1T , wherein the fluorescent light-emitting material:TTA promoter molar ratio is in the range of 80:20-99.9:0.1; and
a second light-emitting layer between the anode and the cathode and adjacent to the first light-emitting layer, the second light-emitting layer comprising a phosphorescent material having a triplet excited state energy level T 1P wherein T 1P >T 1T .

2. The organic light-emitting device according to claim 1 , wherein the TTA promoter has a singlet excited state energy level S 1T and the fluorescent light-emitting material has a singlet excited energy level S 1F wherein S 1T >S 1F .

3. The organic light-emitting device according to claim 1 , wherein the fluorescent light-emitting material is blended with the TTA promoter.

4. The organic light-emitting device according to claim 1 , wherein the TTA promoter is bound to the fluorescent light-emitting material.

5. The organic light-emitting device according to claim 1 , wherein the fluorescent light-emitting material is a blue light-emitting material.

6. The organic light-emitting device according to claim 1 , wherein the fluorescent light-emitting material is a polymer comprising repeat units of formula (IV):

wherein Ar 8 and Ar 9 in each occurrence are independently substituted or unsubstituted aryl or heteroaryl, g is greater than or equal to 1, R 13 is H or a substituent; c and d are each independently 1, 2 or 3; and any one of Ar 8 , Ar 9 and R 13 bound directly to a N atom may be linked to another of Ar 8 , Ar 9 and R 13 bound to the same N atom.

7. The organic light-emitting device according to claim 1 , wherein the half-life of triplet excitons on the TTA promoter is at least 1 microsecond.

8. The organic light-emitting device according to claim 1 , wherein the TTA promoter comprises substituted or unsubstituted anthracene.

9. The organic light-emitting device according to claim 1 , wherein the TTA promoter is a polymer comprising repeat units of formula (V):
-(PAH)-  (V)

wherein PAH represents a polyaromatic hydrocarbon that may be unsubstituted or substituted with one or more substituents.

10. The organic light-emitting device according to claim 9 , wherein the TTA promoter is a polymer comprising substituted or unsubstituted repeat units of formula (Va):

11. The organic light-emitting device according to claim 10 , wherein the repeat unit of formula (Va) is substituted with one or more C 1-20 alkyl groups.

12. The organic light-emitting device according to claim 1 , wherein the phosphorescent light-emitting material is a red light-emitting material.

13. The organic light-emitting device according to claim 1 , wherein the device comprises at least one further light-emitting layer.

14. The organic light-emitting device according to claim 13 , wherein the at least one further light-emitting layer is spaced apart from the first light-emitting layer by the second light-emitting layer.

15. The organic light-emitting device according to claim 13 , wherein the at least one further light-emitting layer is a green light-emitting layer.

16. The organic light-emitting device according to claim 13 , wherein the at least one further light-emitting layer is a phosphorescent light-emitting layer.

17. A method of forming an OLED according to claim 1 , comprising the steps of forming, in any order, the first light-emitting layer and second light-emitting layer over one of the anode and the cathode, and forming the other of the anode and the cathode over the first and second light-emitting layers wherein the first and second light-emitting layers are each independently deposited from a solution in at least one solvent followed by evaporation of the at least one solvent.

18. The method according to claim 17 , wherein the first-deposited layer of the first and second light-emitting layers does not dissolve in the at least one solvent used to deposit the second-deposited layer and wherein the first-deposited layer is crosslinked prior to formation of the second-deposited layer.

Assignees

• Cambridge Display Tech Ltd
• Sumitomo Chemical Co

Inventors

• Archer Robert

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• H10K71/00

  Manufacture or treatment specially adapted for the organic devices covered by this subclass · CPC title

• H10K50/11 Primary

  characterised by the electroluminescent [EL] layers · CPC title

• H10K50/121 Primary

  for assisting energy transfer, e.g. sensitization · CPC title

• H01L51/5016 Primary

  Electricity · mapped topic