# US 11,309,504 B2 · Quantum dot light-emitting device and preparation method thereof

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- Number: US 11,309,504 B2
- Document ID: US11309504B2
- Status: Granted
- Kind: B2
- Application number: 16/764,470
- Filed: 2019-12-16
- Published: 2021-07-22
- Granted: 2022-04-19
- Earliest claimed: 2019-01-11
- Assignees: Beijing BOE Technology Development Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Beijing BOE Technology Development Co., Ltd.; BOE Technology Group Co., Ltd.
- Inventors: Dong Li
- Web page: https://patentgrep.com/patent/US11309504B2

## CPC

- H10K 50/115: comprising active inorganic nanostructures, e.g. luminescent quantum dots
- H10K 50/11: characterised by the electroluminescent [EL] layers
- H10K 50/15: Hole transporting layers
- H10K 50/16: Electron transporting layers
- H10K 50/828: Transparent cathodes, e.g. comprising thin metal layers
- H10K 50/814: combined with auxiliary electrodes, e.g. ITO layer combined with metal lines
- H10K 71/00: Manufacture or treatment specially adapted for the organic devices covered by this subclass
- H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
- H10K 2101/40: Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
- H10K 2102/101: {comprising transparent conductive oxides [TCO]}
- H10K 2102/351: {Thickness}
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

The present disclosure relates to the technical field of display, and discloses a quantum dot light-emitting device and a preparation method thereof. The quantum dot light-emitting device includes a first electrode layer, a quantum dot light-emitting layer, an electron transport layer, a second electrode layer and a third electrode layer which are sequentially arranged in a stacked manner, wherein the side, facing away from the first electrode layer, of the third electrode layer is configured as a light exiting side; the second electrode layer and the third electrode layer are transparent electrode layers; and the work function of the second electrode layer is greater than the LUMO energy level of the electron transport layer and smaller than the work function of the third electrode layer.

## Claims

### Claim 1

A quantum dot light-emitting device, comprising a first electrode layer, a quantum dot light-emitting layer, an electron transport layer, a second electrode layer and a third electrode layer which are sequentially arranged in a stacked mode, wherein a side, away from the first electrode layer, of the third electrode layer is configured as a light exiting side; and the second electrode layer and the third electrode layer are transparent electrode layers, and a work function of the second electrode layer is greater than a LUMO energy level of the electron transport layer and smaller than a work function of the third electrode layer;
wherein a thickness of the second electrode layer is 5%-20% of a thickness of the third electrode layer; and
the second electrode layer is an indium zinc material with an oxygen content being 0; and the third electrode layer is an indium zinc oxide material.

### Claim 2 (depends on 1)

The quantum dot light-emitting device according to claim 1, wherein the thickness of the second electrode layer is 1 nm-10 nm; and the thickness of the third electrode layer is 60 mn-100 nm.

### Claim 3 (depends on 1)

The quantum dot light-emitting device according to claim 1, wherein a material of the electron transport layer is zinc oxide nanoparticles or zinc oxide nanoparticles doped with magnesium.

### Claim 4 (depends on 1)

The quantum dot light-emitting device according to claim 1, further comprises a hole injection layer and a hole transport layer which are positioned between the first electrode layer and the quantum dot light-emitting layer; and the hole injection layer is positioned between the first electrode layer and the hole transport layer.

### Claim 5 (depends on 4)

The quantum dot light-emitting device according to claim 4, wherein a material of the hole injection layer is an organic injection material or an inorganic oxide.

### Claim 6 (depends on 4)

The quantum dot light-emitting device according to claim 4, wherein a material of the hole transport layer is an organic transport material or an inorganic oxide.

### Claim 7 (depends on 1)

The quantum dot light-emitting device according to claim 1, further comprises a base substrate; and the base substrate is positioned on a side, away from the third electrode layer, of the first electrode layer, or the base substrate is positioned on a side, away from the first electrode layer, of the third electrode layer.

### Claim 8 (depends on 1)

A method for preparing a quantum dot light-emitting device according to claim 1, comprising:
respectively preparing the first electrode layer, the quantum dot light-emitting layer, the electron transport layer, the second electrode layer and the third electrode layer, wherein the first electrode layer, the quantum dot light-emitting layer, the electron transport layer, the second electrode layer and the third electrode layer are sequentially stacked, and configuring the side, away from the first electrode layer, of the third electrode layer as the light exiting side; wherein the second electrode layer and the third electrode layer are transparent electrode layers, and the work function of the second electrode layer is greater than the LUMO energy level of the electron transport layer and smaller than the work function of the third electrode layer.

### Claim 9 (depends on 8)

The preparation method according to claim 8, wherein the preparing the second electrode layer and the third electrode layer comprises:
depositing the second electrode layer and the third electrode layer in a sputtering mode, wherein a flow of oxygen fed during sputtering of the second electrode layer is smaller than a flow of oxygen fed during sputtering of the third electrode layer.

### Claim 10 (depends on 9)

The preparation method according to claim 9, wherein the preparing the second electrode layer comprises:
depositing an indium zinc oxide film in a sputtering mode, wherein the flow of oxygen is about 0 sccm to 0.2 sccm and a flow of inert gas is about 40 sccm to 60 sccm during sputtering.

### Claim 11 (depends on 9)

The preparation method according to claim 9, wherein the preparing of the third electrode layer comprises:
depositing an indium zinc oxide film in a sputtering mode, wherein the flow of oxygen is about 0.5 sccm to 2 sccm and a flow of inert gas is about 40 sccm to 60 sccm during sputtering.

### Claim 12 (depends on 8)

The preparation method according to claim 8, further comprising:
respectively preparing a hole injection layer and a hole transport layer; wherein the hole injection layer and the hole transport layer are positioned between the first electrode layer and the quantum dot light-emitting layer, and the hole injection layer is positioned between the first electrode layer and the hole transport layer.