Light emitting device, production method thereof, and display panel

Patent metadata

Field	Value
Publication number	US-9716230-B2
Application number	US-201414436949-A
Country	US
Kind code	B2
Filing date	Apr 24, 2014
Priority date	Jan 27, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

The present disclosure provides a light emitting device, a production method thereof, and a display panel, for simplifying the production process of light emitting device and improving the performance of the light emitting device. The light emitting device in the present disclosure comprises a white light emitting layer comprising a polyfluorene blue light material, and red light quantum dots and green light quantum dots doped in the polyfluorene blue light material.

First claim

The invention claimed is:

1. A light emitting device comprising a white light emitting layer, said white light emitting layer comprising:
a polyfluorene blue light material, and
red light quantum dots and green light quantum dots doped in the polyfluorene blue light material;
wherein the polyfluorene blue light material is one or more selected from the group consisting of biphenyl containing branched side chains, a tetraalkyl substituted indenofluorene polymer, a polyfluorene bithiophene alternative copolymer, an alternative copolymer of octyl-bisubstituted fluorene and benzothiadiazde, a binary or ternary random copolymer of fluorene and thiophene, 4.7-dithiophene-2,1,3-benzothiadiazde and 4.7-dithiophene-2,1,3-benzoselenadiazole, or the polyfluorene blue light material consists of ethylenedioxythiophene.

2. The light emitting device according to claim 1 , wherein the doping ratio between the red light quantum dots and green light quantum dots is from 0.5:1 to 0.8:1.

3. The light emitting device according to claim 2 , wherein the doping ratio between the red light quantum dots and green light quantum dots is from 0.6:1 to 0.7:1.

4. The light emitting device according to claim 1 , wherein the doping ratio between the green light quantum dots and polyfluorene blue light material is from 1:1.1 to 1:1.4.

5. The light emitting device according to claim 4 , wherein the doping ratio between the green light quantum dots and the polyfluorene blue light material is from 1:1.2 to 1:1.3.

6. The light emitting device according to claim 1 , wherein the red light quantum dots are Group II-VI element compounds.

7. The light emitting device according to claim 6 , wherein the red light quantum dots are compound semiconductor materials formed of Group II element Zn, Cd, or Hg and Group VI element S, Se, or Te.

8. The light emitting device according to claim 7 , wherein the red light quantum dots are ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, or HgTe.

9. The light emitting device according to claim 1 , wherein the green light quantum dots are Group III-V element compounds.

10. The light emitting device according to claim 9 , wherein the green light quantum dots are compounds formed of B, Al, Ga, or In of Group III and N, P, As, or Sb of Group V.

11. The light emitting device according to claim 10 , wherein the green light quantum dots are BN, BP, BAs, BSb, AN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InAs, InN, InP, or InSb.

12. A display panel comprising:
a color film substrate and an array substrate, wherein the array substrate is provided with a plurality of pixel units, and each pixel unit has a plurality of subpixel units displaying different colors, and wherein the array substrate is provided with the light emitting device according to claim 1 at a position corresponding to each subpixel unit; and
a color filter corresponding to each subpixel unit, wherein the color filter is positioned between the white light emitting layer of the light emitting device and the color film substrate.

13. A production method of a light emitting device, comprising:
forming an anode and a hole injection layer in this order on a substrate;
forming a white light emitting layer on the hole injection layer, the white light emitting layer comprising a polyfluorene blue light material, and red light quantum dots and green light quantum dots doped into the polyfluorene blue light material; and
forming an electron transferring layer and a cathode in this order on the white light emitting layer;
wherein the polyfluorene blue light material is one or more selected from the group consisting of biphenyl containing branched side chains, a tetraalkyl substituted indenofluorene polymer, a polyfluorene bithiophene alternative copolymer, an alternative copolymer of octyl-bisubstituted fluorene and benzothiadiazde, a binary or ternary random copolymer of fluorene and thiophene, 4.7-dithiophene-2,1,3-benzothiadiazde and 4.7-dithiophene-2,1,3-benzoselenadiazole, or the polyfluorene blue light material consists of ethylenedioxythiophene.

14. The method according to claim 13 , wherein the white light emitting layer is formed on the hole injection layer by:
dissolving a polyfluorene or derivative thereof, red light quantum dots and green light quantum dots together into an organic solvent, to form the polyfluorene blue light material doped with red light quantum dots and green light quantum dots; and
coating the polyfluorene blue light material doped with the red light quantum dots and the green light quantum dots onto the hole injection layer, to form the white light emitting layer.

15. The method according to claim 14 , wherein the doping ratio between the red light quantum dots and the green light quantum dots is from 0.5:1 to 0.8:1.

16. The method according to claim 15 , wherein the doping ratio between the red light quantum dots and the green light quantum dots is from 0.6:1 to 0.7:1.

17. The method according to claim 14 , wherein the doping ratio between the green light quantum dots and the polyfluorene or derivative thereof is from 1:1.2 to 1:1.3.

18. The method according to claim 14 , wherein the organic solvent comprises toluene, chlorobenzene or trichloromethane.

19. The method according to claim 14 , wherein the doping ratio between the green light quantum dots and the polyfluorene or derivative thereof is from 1:1.1 to 1:1.4.

Assignees

• Boe Technology Group Co Ltd

Inventors

• Tang Chen
• Gu Jingxia

Classifications

• C09K11/06 Primary

  containing organic luminescent materials · CPC title

• H01L27/322

  Electricity · mapped topic

• H01L51/0039 Primary

  Electricity · mapped topic

• C09K11/881

  Chalcogenides · CPC title

• C09K2211/1416

  Condensed systems · CPC title