# US 12,604,603 B2 · Light-emitting element and display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,604,603 B2
- Document ID: US12604603B2
- Status: Granted
- Kind: B2
- Application number: 17/918,889
- Filed: 2020-04-22
- Published: 2023-09-14
- Granted: 2026-04-14
- Earliest claimed: 2020-04-22
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: Ryo Kitamura
- Web page: https://patentgrep.com/patent/US12604603B2

## CPC

- H10K 50/166: {comprising a multilayered structure}
- H05B 33/14: characterised by the chemical or physical composition or the arrangement of the electroluminescent material {, or by the simultaneous addition of the electroluminescent material in or onto the light source}
- H10K 50/115: comprising active inorganic nanostructures, e.g. luminescent quantum dots
- H10K 50/156: {comprising a multilayered structure}
- H10K 59/35: comprising red-green-blue [RGB] subpixels
- H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
- H10K 2102/331: {Nanoparticles used in non-emissive layers, e.g. in packaging layer}
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL

## Abstract

A light-emitting element according to an aspect of the disclosure, comprising: a first electrode; a second electrode; a light-emitting layer disposed between the first electrode and the second electrode; and a charge transport layer disposed between the first electrode and the light-emitting layer. The charge transport layer includes a first layer and a second layer closer to the first electrode relative to the first laver. The first layer and the second layer include nanoparticles containing an identical semiconductor A particle size of the nanoparticle of the second layer is larger than a particle size of the nanoparticle of the first layer.

## Claims

### Claim 1

A display device, comprising:
a first light-emitting element configured to emit red light;
a second light-emitting element configured to emit green light; and
a third light-emitting element configured to emit blue light,
wherein each of the first, second, and third light-emitting elements includes:
an anode,
a cathode,
a light-emitting layer disposed between the anode and the cathode, and
an electron transport layer disposed between the cathode and the light-emitting layer, and including a first layer and a second layer closer to the cathode relative to the first layer,
in each of the first, second, and third light-emitting elements, the first layer and the second layer include nanoparticles containing an identical semiconductor, and a particle size of each nanoparticle of the second layer is larger than a particle size of each nanoparticle of the first layer, and
the particle size of each nanoparticle included in the first layer of the first light-emitting element is larger than the particle size of each nanoparticle included in the first layer of the second light-emitting element, and the particle size of each nanoparticle included in the first layer of the second light-emitting element is larger than the particle size of each nanoparticle included in the first layer of the third light-emitting element.

### Claim 2 (depends on 1)

The display device according to claim 1,
wherein the second layer of the first light-emitting element, the second layer of the second light-emitting element, and the second layer of the third light-emitting element form a common layer.

### Claim 3 (depends on 1)

The display device according to claim 1,
wherein, in each of the first, second, and third light-emitting elements, the first layer and the light-emitting layer are in contact with each other, and the second layer and the cathode are in contact with each other, and
the particle size of each nanoparticle included in the second layer of the first light-emitting element, the particle size of each nanoparticle included in the second layer of the second light-emitting element, and the particle size of each nanoparticle included in the second layer of the third light-emitting element are equivalent to one another.

### Claim 4 (depends on 1)

The display device according to claim 1,
wherein a thickness of the electron transport layer of the first light-emitting element is less than a thickness of the electron transport layer of the second light-emitting element, and the thickness of the electron transport layer of the second light-emitting element is less than a thickness of the electron transport layer of the third light-emitting element.