Organic light-emitting composition, device and method

Patent metadata

Field	Value
Publication number	US-10033019-B2
Application number	US-201314091212-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Nov 30, 2012
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A light-emitting composition comprising a mixture of a fluorescent light-emitting material a triplet-accepting copolymer comprising a triplet-accepting repeat unit and a repeat unit of formula (I):

wherein A is a divalent group; R 1 independently in each occurrence is a substituent; R 2 in each occurrence is H or a substituent; and x independently in each occurrence is 0, 1, 2 or 3.

First claim

The invention claimed is:

1. A light-emitting composition comprising a mixture of a fluorescent light-emitting material and a triplet-accepting copolymer wherein the triplet-accepting copolymer has a lowest triplet excited state energy level that is lower than a lowest triplet excited state energy level of the fluorescent light-emitting material, the triplet accepting copolymer comprising a triplet-accepting repeat unit, a repeat unit of formula (I), and one or more further co-repeat units;

wherein A is a divalent group of formula —CR 2 2 —; R 1 independently in each occurrence is a C 1-40 hydrocarbyl group;
R 2 in each occurrence is H; a C 1-40 hydrocarbyl group; or a C 1-20 alkyl, wherein one or more non-adjacent C atoms of the C 1-20 alkyl are replaced by an aryl or heteroaryl group, O, S, C═O, COO, or NR 11 , wherein R 11 is a C 1-10 alkyl; and
x independently in each occurrence is 0, 1, 2 or 3;
wherein the copolymer comprises 10-40 mol % of repeat units of formula (I); and wherein light emission from the composition has a peak wavelength that is the same as or no more than 10 nm longer than a peak wavelength of light emitted from the fluorescent light-emitting material alone wherein the copolymer comprises 5-40 mol % of the further co-repeat units and the further co-repeat units are phenylene, fluorine, or dihydrophenthrene repeat units, each of which is unsubstituted or substituted with one or more substituents.

2. A light-emitting composition according to claim 1 , wherein each R 2 is independently selected from the group consisting of H and C 1-20 alkyl.

3. A light-emitting composition according to claim 1 wherein the triplet-accepting repeat unit comprises a polycyclic aromatic co-repeat unit that may be unsubstituted or substituted with one or more substituents.

4. A light-emitting composition according to claim 3 wherein the triplet-accepting repeat unit is selected from anthracene and pyrene, each of which may be unsubstituted or substituted with one or more substituents.

5. A light-emitting composition according to claim 4 wherein the triplet-accepting repeat unit is selected from repeat units of formulae (II) and (III):

wherein R 4 in each occurrence is independently a C 1-40 hydrocarbyl group or a C 1-20 alkyl, wherein one or more non-adjacent C atoms of the C 1-20 alkyl are replaced by O, S, C═O, COO or NR 11 , wherein R 11 is a C 1-20 alkyl group; each a is independently 0, 1 or 2; each b is independently 0, 1 or 2; and each c is independently 0, 1, 2, 3 or 4.

6. A light-emitting composition according to claim 5 wherein the repeat unit of formula (II) has formula (IIa):

7. A light-emitting composition according to claim 5 or 6 wherein at least one a and/or at least one b is at least 1.

8. A light-emitting composition according to claim 1 wherein the fluorescent light-emitting material is a polymer.

9. A light-emitting composition according to claim 8 wherein the fluorescent light-emitting polymer comprises repeat units of formula (IX):

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, alkyl, Ar 10 , a branched or linear chain of Ar 10 groups, or a crosslinkable unit that is bound directly to the N atom of formula (IX) or spaced apart therefrom by a spacer group, wherein Ar 10 in each occurrence is independently optionally substituted aryl or heteroaryl, and c and d are each independently 1, 2, or 3; and any two of Ar 8 , Ar 9 and R 13 directly bound to the same N atom may be linked by a direct bond or a divalent linking group to form a ring.

10. A light-emitting composition according to claim 8 or 9 wherein the fluorescent light-emitting polymer comprises one or more co-repeat units selected from phenylene, fluorene and dihydrophenanthrene repeat units, each of which may be unsubstituted or substituted with one or more C 1-40 hydrocarbyl groups.

11. A light-emitting composition according to claim 1 wherein the fluorescent light-emitting material:triplet-accepting polymer weight ratio is in the range of about 99.5:0.5 to about 70:30.

12. A light-emitting composition consisting essentially of a fluorescent light-emitting material and a triplet-accepting polymer according to claim 1 .

13. A formulation comprising a composition according to claim 1 and at least one solvent.

14. An organic light-emitting device comprising an anode, a cathode and a light-emitting layer between the anode and the cathode wherein the light-emitting layer comprises a composition according to claim 1 .

15. A method of forming an organic light-emitting device according to claim 14 , the method comprising the steps of forming the light-emitting layer over one of the anode and cathode, and forming the other of the anode and cathode over the light-emitting layer.

16. A method according to claim 15 wherein the light-emitting layer is formed by depositing the formulation of claim 13 over one of the anode and cathode and evaporating the at least one solvent.

Assignees

• Cambridge Display Tech Ltd
• Sumitomo Chemical Co
• Cambridge Display Tech Ltd

Inventors

• Jakobsson Fredrik
• Nielsen Christian
• Pillow Jonathan
• Distasio Francesco
• Snedden Edward

Classifications

• C09K2211/1416

  Condensed systems · CPC title

• C08G2261/124

  alternating · CPC title

• C08G2261/5242

  electrophosphorescent · CPC title

• C08G2261/411

  Suzuki reactions · CPC title

• C08G2261/95

  Use in organic luminescent diodes · CPC title