Perovskite compound-based electroluminescent layer and light emitting device comprising same

Patent metadata

Field	Value
Publication number	US-12486448-B2
Application number	US-202118044839-A
Country	US
Kind code	B2
Filing date	Sep 10, 2021
Priority date	Sep 11, 2020
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

An electroluminescent layer according to the present invention comprises a core-shell particle comprising a perovskite crystal core and a shell of a dielectric polymer, wherein a charge transfer pathway to the perovskite crystal core is formed by dielectric breakdown of the dielectric polymer. The electroluminescent layer according to the present invention can prevent the deterioration of perovskite crystals due to external moisture, oxygen, or the like since the perovskite crystal core is enclosed and protected by the dielectric polymer and can have improved charge transfer and injection efficiencies since charges are directly transferred and injected to the perovskite crystals through the charge transfer pathway formed by dielectric breakdown of the dielectric polymer.

First claim

The invention claimed is:

1 . An electroluminescent layer comprising: core-shell particles including a perovskite crystal core and a dielectric polymer shell, wherein a charge transfer pathway to the perovskite crystal core is formed by dielectric breakdown of the dielectric polymer.

2 . The electroluminescent layer of claim 1 , wherein the core-shell particles adjacent to each other are bound to each other.

3 . The electroluminescent layer of claim 2 , wherein the core-shell particles are the most closely packed.

4 . An electroluminescent layer comprising: a dielectric polymer matrix; perovskite crystals which are embedded in the dielectric polymer matrix and has a closest packed structure; and a charge transfer pathway which is formed by dielectric breakdown of the dielectric polymer and connects perovskite crystals.

5 . The electroluminescent layer of claim 1 , wherein a spacing between the perovskite crystals is 10 nm or less.

6 . The electroluminescent layer of claim 1 , wherein the dielectric polymer has a dielectric constant of 2 or more.

7 . The electroluminescent layer of claim 1 , wherein the dielectric polymer includes an amphiphilic block copolymer.

8 . The electroluminescent layer of claim 1 , wherein the charge transfer pathway is a carbon channel produced by dielectric breakdown.

9 . The electroluminescent layer of claim 1 , wherein the core-shell particles adjacent to each other are integrally connected by polymerization between the shells.

10 . The electroluminescent layer of claim 1 , wherein the perovskite crystals have a diameter of 10 to 300 nm.

11 . The electroluminescent layer of claim 1 , wherein the perovskite crystals satisfy the following Chemical Formulae 1 to 4:
AMX 3   (Chemical Formula 1)
A 2 MX 4   (Chemical Formula 2)
AMX 4   (Chemical Formula 3)
A 3 MX 5   (Chemical Formula 4)
wherein A is an alkali metal, M is a divalent metal, and X is a halogen.

12 . A light emitting device comprising:
a first electrode; a hole transport layer placed on the first electrode; the electroluminescent layer according to claim 1 placed on the hole transport layer; an electron transport layer placed on the electroluminescent layer; and a second electrode placed on the electron transport layer.

13 . A method of producing an electroluminescent layer, the method comprising: applying voltage to a precursor film in which perovskite crystals are enclosed in a dielectric polymer to cause dielectric breakdown of the dielectric polymer.

14 . The method of producing an electroluminescent layer of claim 13 , further comprising:
before the applying of voltage, a) injecting a perovskite solution including an alkali metal halide, a divalent metal halide, a surfactant, and a first polymerizable monomer into an aprotic solvent to produce perovskite crystals modified by a polymerizable monomer; b) using a polymerization solution including the perovskite crystals modified by a polymerizable monomer, a second polymerizable monomer, and an initiator to produce core-shell particles having a dielectric polymer shell formed by polymerizing the second polymerizable monomer on a perovskite crystal surface; and c) producing a film of the core-shell particles.

15 . The method of producing an electroluminescent layer of claim 14 , further comprising:
after the process of c) and before the applying of voltage, d) spraying an initiator solution including an initiator and an organic solvent onto the film of the core-shell particles and activating the initiator to bind the shells between the core-shell particles adjacent to each other.

16 . The method of producing an electroluminescent layer of claim 15 , wherein in the process of d), the organic solvent is a solvent dissolving the dielectric polymer.

17 . The method of producing an electroluminescent layer of claim 14 , wherein in the process of d), the initiator solution further includes a third polymerizable monomer.

18 . The method of producing an electroluminescent layer of claim 14 , wherein the first polymerizable monomer and the second polymerizable monomer are independently of each other one or two or more selected from acrylate-based monomers, methacrylate-based monomers, styrene-based monomers, and siloxane-based monomers.

19 . The method of producing an electroluminescent layer of claim 13 , further comprising:
before the applying of voltage, I) dissolving an amphiphilic block copolymer in a solvent to produce a micelle solution of the amphiphilic block copolymer; II) adding a divalent metal halide to the micelle solution and performing stirring; III) adding an alkali metal halide to the micelle solution to which the divalent metal halide has been added and performing stirring to produce core-shell particles having a perovskite crystal core and an amphiphilic block copolymer shell which is a dielectric polymer shell; and IV) producing a film of the core-shell particles.

20 . The method of producing an electroluminescent layer of claim 19 , wherein the amphiphilic block copolymer includes a polyvinylpyridine-based polymer block.

21 . The method of producing an electroluminescent layer of claim 20 , wherein the polyvinylpyridine-based polymer block is poly(2-vinylpyridine) or poly(4-vinylpyridine).

22 . The method of producing an electroluminescent layer of claim 20 , wherein a weight ratio of a hydrophobic polymer block:the polyvinylpyridine-based polymer block in the amphiphilic block copolymer is 1:0.8 to 1.2.

23 . The method of producing an electroluminescent layer of claim 20 , wherein the solvent of the process of I) is a non-solvent of the perovskite crystals, and after the process of II) and before the process of III), removing the divalent metal halide remaining as a solid phase is further comprised.

Assignees

• Univ Yonsei Iacf

Inventors

• Kim Jiwon
• Kim Dongjun
• Oh Seoyeah
• Park Jihyeon
• Kim Geonho
• Lee Jiyeon
• Yoon Seoyoung

Classifications

• H10K85/50

  Organic perovskites; Hybrid organic-inorganic perovskites [HOIP], e.g. CH3NH3PbI3 · CPC title

• C09K11/665

  with alkali or alkaline earth metals · CPC title

• H10K85/111

  comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene · CPC title

• H10K71/12

  using liquid deposition, e.g. spin coating · CPC title

• H10K50/115

  comprising active inorganic nanostructures, e.g. luminescent quantum dots · CPC title