Organic light-emitting device and method

Patent metadata

Field	Value
Publication number	US-9812647-B2
Application number	US-201113805297-A
Country	US
Kind code	B2
Filing date	Jun 24, 2011
Priority date	Jun 25, 2010
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

Composition which may be useful in an organic light emitting diode, the composition having a fluorescent light-emitting polymer with light-emitting repeat units, and a triplet-accepting unit mixed with the light-emitting polymer.

First claim

The invention claimed is:

1. A composition comprising a fluorescent light-emitting polymer mixed with a triplet-accepting polymer comprising a repeat unit of formula (IIb):
(TAU-Spacer) m   (IIb)

wherein TAU represents a triplet-accepting unit selected from the group consisting of: an anthracene TAU which is unsubstituted or substituted with one or more alkyl groups,

wherein * denotes the linking points for linking the repeat unit into the polymer chain, Ak is alkyl, and R is H or a substituent; Spacer is a spacer group selected from the group consisting of phenylene, biphenylene, and fluorene, and m is at least 2; wherein the triplet accepting polymer has a triplet energy level lower than that of the fluorescent light-emitting polymer.

2. A composition according to claim 1 wherein the composition comprises at least one of a hole transporting material and an electron transporting material.

3. A composition according to claim 1 wherein the light-emitting polymer comprises a light-emitting repeat unit and at least one of repeat units providing electron transport and repeat units providing hole transport.

4. A composition according to claim 1 wherein the light-emitting polymer comprises arylamine repeat units.

5. A composition according to claim 4 wherein the arylamine repeat units are units of formula (V):

wherein Ar 1 and Ar 2 are optionally substituted aryl or heteroaryl groups, n is greater than or equal to 1, and R is H or a substituent.

6. A composition according to claim 5 wherein n is 1 or 2.

7. A composition according to claim 1 wherein the light-emitting polymer comprises aryl or heteroaryl repeat units.

8. A composition according to claim 7 wherein the light-emitting polymer comprises repeat units of formula (IV):

wherein R 1 and R 2 are independently H or a substituent, and R 1 and R 2 are optionally linked to form a ring.

9. A composition according to claim 1 wherein the composition has a photoluminescent light emission peak wavelength in the range of 400 to 500 nm.

10. A formulation comprising a solvent and a composition according to claim 1 .

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

12. A method of forming an organic light-emitting device according to claim 11 , comprising the steps of:
depositing a formulation comprising a solvent and a composition comprising the fluorescent light-emitting polymer mixed with the triplet-accepting polymer; and
evaporating the solvent.

13. A method, comprising:
applying a voltage to 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 comprising a fluorescent light-emitting polymer mixed with a triplet-accepting polymer comprising a TAU of formula (IIb):
(TAU-Spacer) m   (IIb)

wherein TAU represents a triplet-accepting unit selected from the group consisting of: an anthracene repeat unit which is unsubstituted or substituted with one or more alkyl groups,

wherein * denotes the linking points for linking the repeat unit into the polymer chain, Ak is alkyl, and R is H or a substituent; Spacer is a spacer group selected from the group consisting of phenylene, biphenylene, and fluorene, and m is at least 2,
wherein the triplet-accepting unit accepts triplet excitons generated by the light-emitting polymer.

14. A method according to claim 13 wherein the triplet-accepting unit quenches triplet excitons generated by the light-emitting polymer.

15. A method according to claim 13 wherein the triplet-accepting unit mediates triplet-triplet annihilation of triplet excitons transferred from the light-emitting polymer to the triplet-accepting unit.

16. The composition according to claim 1 , wherein the composition is a fluorescent composition which emits substantially no phosphorescent light.

17. The composition according to claim 1 , wherein delayed fluorescence is produced by the composition.

Assignees

• Pillow Jonathan
• Roberts Matthew
• Pintani Martina
• King Simon
• Cass Michael
• Cambridge Display Tech Ltd
• Sumitomo Chemical Co

Inventors

• Pillow Jonathan
• Roberts Matthew
• Pintani Martina
• King Simon
• Cass Michael

Classifications

• C08G2261/3245

  containing nitrogen and oxygen as heteroatoms · CPC title

• C09K11/06

  containing organic luminescent materials · CPC title

• C08G2261/228

  Polymers, i.e. more than 10 repeat units · CPC title

• C08G61/122

  derived from five- or six-membered heterocyclic compounds, other than imides · CPC title

• C07C15/18

  containing at least one group with formula[IMAGE cpc-sch-C07C-0954.gif] · CPC title