Crosslinked emissive layer containing quantum dots for light-emitting device and method for making same

• US 10,581,007 B2
• Filed: 03/27/2018
• Issued: 03/03/2020
• Est. Priority Date: 03/27/2018
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Angioni, Enrico, Palles-Dimmock, James Andrew Robert, Boardman, Edward Andrew, Smeeton, Tim Michael
• Primary Examiner(s): Vu, David
• Application Number:
  US15/937,073
• Publication Number:
  US 20190305240A1
• Time in Patent Office: 707 Days
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H10K 50/115 comprising active inorganic nanostructures, e.g. luminescent quantum dots
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene

Abstract

A light-emitting device includes an anode; a cathode; and an emissive layer disposed between the anode and the cathode, the emissive layer including quantum dots dispersed in a crosslinked matrix formed from one or more crosslinkable charge transport materials. A method of forming the emissive layer of a light-emitting device includes depositing a mixture including quantum dots and one or more crosslinkable charge transport materials on a layer; and subjecting at least a portion of the mixture to UV activation to form an emissive layer including quantum dots dispersed in a crosslinked matrix.

Claims

1. A light-emitting device, comprising:

an anode;

a cathode; and

an emissive layer disposed between the anode and the cathode, the emissive layer comprising quantum dots comprising ligands, the quantum dots dispersed in a crosslinked matrix formed at least partially from one or more crosslinkable charge transport materials other than the ligands.

2. The light-emitting device of claim 1, wherein the ligands interact with the one or more crosslinkable charge transport materials, and the quantum dots form part of the crosslinked matrix.

3. The light-emitting device of claim 1, wherein the ligands have one or more functional groups.

4. The light-emitting device of claim 3, wherein the ligands include one or more functional groups that interact with at least one of the one or more crosslinkable charge transport materials in forming the part of the crosslinked matrix, the one or more functional groups comprising an alkene.

5. The light-emitting device of claim 3, wherein the ligands include one or more functional groups that interact with at least one of the one or more crosslinkable charge transport materials in forming the part of the crosslinked matrix, the one or more functional groups comprising an alkyne.

6. The light-emitting device of claim 3, wherein the ligands include one or more functional groups that interact with at least one of the one or more crosslinkable charge transport materials in forming the part of the crosslinked matrix, the one or more functional groups comprising a carbonyl functional group.

7. The light-emitting device of claim 3, wherein the ligands include one or more functional groups that interact with at least one of the one or more crosslinkable charge transport materials in forming the part of the crosslinked matrix, the one or more functional groups comprising a carboxyl functional group.

8. The light-emitting device of claim 1, wherein the one or more crosslinkable charge transport material comprises one or more hole transport materials.

9. The light-emitting device of claim 1, wherein the one or more crosslinkable charge transport material comprises one or more electron transport materials.

10. The light-emitting device of claim 1, further comprising a hole transport layer disposed between the anode and the emissive layer.

11. The light-emitting device of claim 10, wherein the hole transport layer is crosslinked with the matrix of the emissive layer.

12. The light-emitting device of claim 10, further comprising a hole injection layer disposed between the anode and the hole transport layer.

13. The light-emitting device of claim 1, further comprising an electron transport layer disposed between the cathode and the emissive layer.

14. The light-emitting device of claim 13, wherein the electron transport layer is crosslinked with the matrix of the emissive layer.

15. The light emitting device of claim 1, wherein the emissive layer further comprises one or more photo initiators.

16. The light-emitting device of claim 1, wherein the crosslinked matrix is formed using one or more photo initiators.

17. The light-emitting device of claim 1, wherein the ligands do not interact with the one or more crosslinkable charge transport materials.

18. The light-emitting device of claim 1, wherein at least one of the one or more crosslinkable charge transport materials comprises at least one of a tertiary, secondary, or primary aromatic amine.

19. The light-emitting device of claim 1, wherein at least one of the one or more crosslinkable charge transport materials comprises at least one of an oxetane or epoxide functional group.

20. The light-emitting device of claim 1, wherein the ligands are provided at an outer surface of the quantum dots.