Organic light emitting device

Patent metadata

Field	Value
Publication number	US-10529945-B2
Application number	US-201515515734-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Sep 30, 2014
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

An organic light-emitting device (100) comprising an anode (103); a cathode (109); a light-emitting layer (107) between the anode and the cathode; a first hole-transporting layer (105A) comprising a first conjugated hole-transporting polymer between the anode and the light-emitting layer; and a second hole-transporting layer (105B) comprising a second conjugated hole-transporting polymer between the first hole-transporting layer and the light-emitting layer, wherein a lowest excited state energy level of the first hole-transporting polymer is lower than the lowest excited state energy of the second hole-transporting polymer.

First claim

The invention claimed is:

1. An organic light-emitting device comprising an anode; a cathode; a light-emitting layer between the anode and the cathode; a first hole-transporting layer comprising a first conjugated hole-transporting polymer between the anode and the light-emitting layer; and a second hole-transporting layer comprising a second conjugated hole-transporting polymer between the first hole-transporting layer and the light-emitting layer, wherein a lowest excited state energy level of the first hole-transporting polymer is lower than the lowest excited state energy of the second hole-transporting polymer; wherein a difference in HOMO level of the first and second hole-transporting polymers is no more than 0.3 eV.

2. An organic light-emitting device according to claim 1 wherein the light-emitting layer comprises a fluorescent light-emitting material and the lowest excited state energy is a lowest singlet excited state energy.

3. An organic light-emitting device according to claim 1 wherein the light-emitting layer comprises a phosphorescent light-emitting material and the lowest excited state energy is a lowest triplet excited state energy.

4. An organic light-emitting device according to claim 1 wherein the first and second hole-transporting polymers each comprise a repeat unit of formula (III):

wherein Ar 8 , Ar 9 and Ar 10 in each occurrence are independently substituted or unsubstituted aryl or heteroaryl g is 0, 1 or 2; R 13 is H or a substituent; c, d and e are each independently 1, 2 or 3; and any two aromatic or heteroaromatic groups bound directly to the same N atom may be linked by a direct bond or divalent linking group.

5. An organic light-emitting device according to claim 4 wherein the first and second hole-transporting polymers both comprise a same unit of formula (III).

6. An organic light-emitting device comprising an anode; a cathode; a light-emitting layer between the anode and the cathode; a first hole-transporting layer comprising a first conjugated hole-transporting polymer between the anode and the light-emitting layer; and a second hole-transporting layer comprising a second conjugated hole-transporting polymer between the first hole-transporting layer and the light-emitting layer, wherein a lowest excited state energy level of the first hole-transporting polymer is lower than the lowest excited state energy of the second hole-transporting polymer; wherein at least one of the first and second hole-transporting layers comprises a fluorescent or phosphorescent light-emitting material that emits light when the device is in use.

7. An organic light-emitting device according to claim 6 wherein the second hole-transporting layer comprises the fluorescent or phosphorescent light-emitting material.

8. An organic light-emitting device according to claim 6 wherein the fluorescent or phosphorescent light-emitting material emits a red light when the device is in use.

9. An organic light-emitting device according to claim 1 wherein a hole-injection layer is provided between the anode and the first hole-transporting layer.

10. An organic light-emitting device according to claim 1 wherein each of the first and second hole-transporting layers is crosslinked.

11. An organic light-emitting device according to claim 1 wherein the device emits white light.

Assignees

• Cambridge Display Tech Ltd
• Sumitomo Chemical Co

Inventors

• Archer Robert
• King Simon

Classifications

• C08G2261/411

  Suzuki reactions · CPC title

• C08G2261/135

  Cross-linked structures · CPC title

• C08G2261/3162

  Arylamines · CPC title

• C08G2261/95

  Use in organic luminescent diodes · CPC title

• C08G2261/1624

  of Os, Ir, Pt, Ru, Rh or Pd · CPC title