Electroluminescent device

Patent metadata

Field	Value
Publication number	US-11362298-B2
Application number	US-202016829899-A
Country	US
Kind code	B2
Filing date	Mar 25, 2020
Priority date	Nov 28, 2014
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

Broadly speaking, embodiments of the present invention provide a solid state light-emitting device and a method of manufacturing the solid state light-emitting device. The method comprises preparing a thin layer of semiconducting perovskite nanoparticles embedded in a matrix or blend of a material that has a wider band gap than the semiconducting perovskite nanoparticles. In embodiments, the method comprises blending a solution of a semiconducting perovskite material or a precursor therefor with a solution of a material that has a wider band gap than the semiconducting perovskite material or a precursor therefor followed by removal of the solvent from the mixture thus formed, to give the semiconducting perovskite nanoparticles embedded in a matrix or blend of the material that has a wider band gap than the semiconducting perovskite nanoparticles.

First claim

The invention claimed is:

1. An emissive phosphor comprising a layer of semiconducting perovskite nanoparticles embedded in a matrix or blend of an insulating material, wherein the insulating material comprises an insulating polymer or an insulating organic molecule, and wherein the semiconducting perovskite comprises perovskite with an AMX 3 structure, where A is a monovalent cation, M is a divalent cation and X is a halide anion, wherein the monovalent cation A is:
of the form [R 1 R 2 N═CH—NR 3 R 4 ] + :

wherein each of R 1 , R 2 , R 3 and R 4 may be the same or different and is selected from hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, and an unsubstituted or substituted Cs-Cis aryl group; and/or
of the form (R 1 R 2 N)(R 3 R 4 )N═NR 5 R 6 :

wherein each of R 1 R 2 , R 3 , R 4 , R 5 and R 6 may be the same or different and is selected from hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, and an unsubstituted or substituted C 5 -C 18 aryl group; and/or
an alkali metal cation.

2. The emissive phosphor of claim 1 , wherein the insulating material is an insulating polymer.

3. The emissive phosphor of claim 2 , wherein the insulating polymer is a polar polymer.

4. The emissive phosphor of claim 1 , wherein the insulating material is an insulating organic molecule.

5. The emissive phosphor of claim 4 , wherein the insulating organic molecule is a polar organic molecule.

6. The emissive phosphor of claim 1 , wherein the insulating material is a polyimide, including a polyamic acid of benzophenone tetracarboxylic dianhydride 4,4-oxydianiline m-phenylenediamine polymer (PIP) having the following formula:

is polystyrene; or
is poly (9-vinylcarbazole), of the form:

is the organic compound 4,4-bis(N-carbazolyl)-1,1-biphenyl, of the form:

7. The emissive phosphor of claim 1 , wherein the thickness of the layer of semiconducting perovskite nanoparticles embedded in the matrix or blend of the insulating material is ≤500 nm.

8. The emissive phosphor of claim 1 , wherein X is: a halide anion selected from chloride, bromide, iodide, and fluoride and, in the AMX 3 structure each halide may be the same or different.

9. The emissive phosphor of claim 1 , wherein the perovskite material has an A′ 1-i B′ i MX 3 structure, wherein:
A′ and B′ are each a monovalent cation having the same definition as A in claim 1 , where A′ and B′ are different; and,
i is between 0 and 1;
or
wherein the perovskite material has an AMX′ 3-k Y′ k structure, wherein:
X′ and Y′ are each a halide anion having the same definition as X in claim 1 , where X‘ and Y’ are different; and
k is between 0 and 3;
or
wherein the perovskite material has an AM′ 1-j N′ j X 3 structure, wherein:
M′ and N′ are each a divalent metal cation having the same definition as M in claim 1 , where M′ and N′ are different; and
j is between 0 and 1;
or
wherein the perovskite material has an A″ 1-i B″ i M″ 1-i N″ i X″ 3-k Y″ k structure, wherein:
A″ and B″ are each a monovalent cation having the same definition as A in claim 1 , where A″ and B″ are different;
M″ and N″ are each a divalent metal cation having the same definition as M in claim 1 , where M″ and N″ are different;
X″ and Y″ are each a halide anion having the same definition as X in claim 1 , where X″ and Y″ are different; and
where i is between 0 and 1, j is between 0 and 1, and k is between 0 and 3.

10. The emissive phosphor of claim 1 , wherein the semiconducting perovskite nanoparticles are semiconducting perovskite nanocrystals.

11. The emissive phosphor of claim 1 , wherein the ratio by weight of semiconducting perovskite nanoparticles: the insulating material is from 0.01:1 to 20:1.

12. A method to select wavelengths emitted by the emissive phosphor of claim 1 , said method comprising: selecting a ratio of semiconducting perovskite nanoparticles to the insulating material, and embedding the semiconducting perovskite nanoparticles in a matrix or blend of the insulating material according to the ratio to provide an emissive phosphor having said selection of said wavelengths; and/or selecting a semiconducting perovskite nanoparticle material or a precursor therefor and/or selecting the insulating material, and embedding the semiconducting perovskite nanoparticle material or precursor therefor in the insulating material, to provide an emissive phosphor having said selection of said wavelengths.

13. A method to select wavelengths emitted by the emissive phosphor of claim 1 , said method comprising varying the size of the perovskite nanoparticles, and embedding the perovskite nanoparticles with the varied size in a matrix or blend of the insulating material, to provide an emissive phosphor having said selection of said wavelengths.

14. The emissive phosphor of claim 1 , wherein the ratio by weight of semiconducting perovskite nanoparticles: the insulating material is from 0.01:1 to 2:1.

15. The emissive phosphor of claim 1 , wherein the ratio by weight of semiconducting perovskite nanoparticles: the insulating material is from 0.1:1 to 10:1.

16. The emissive phosphor of claim 1 , wherein the ratio by weight of semiconducting perovskite nanoparticles: the insulating material is from 1:1 to 5:1.

17. The emissive phosphor of claim 1 , wherein the ratio by weight of semiconducting perovskite nanoparticles: the insulating material is from 1:1 to 2:1.

18. The emissive phosphor of claim 1 , wherein the alkali metal cation is caesium (Cs + ) or rubidium (Rb + ).

Assignees

• Cambridge Entpr Ltd
• King Abdulaziz City For Science & Tech

Inventors

• Friend Richard Henry
• Tan Zhi Kuang
• Li Guangru
• Di Dawei
• Greenham Neil C

Classifications

• H10K85/50

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

• H10K50/18

  Carrier blocking layers · CPC title

• H10K85/30 Primary

  Coordination compounds · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E10/549

  Organic PV cells · CPC title