# US 12,772,656 B2 · Display element and display device comprising light diffusing layer and P-type and N-type charge generation layers

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- Number: US 12,772,656 B2
- Document ID: US12772656B2
- Status: Granted
- Kind: B2
- Application number: 18/578,377
- Filed: 2023-03-29
- Published: 2025-07-17
- Granted: 2026-10-20
- Earliest claimed: 2023-03-29
- Assignees: Chongqing BOE Display Technology Co., Ltd.; Beijing BOE Technology Development Co., Ltd.
- Applicants: Chongqing BOE Display Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Inventors: Liu He; Jaeho Lee; Dongyu Gao; Xunfei Tong; Han Nie; Gen Zhao; Tong Lv; Jingwei Huang; Yingxiong Deng; Chengji Deng; Jia Chen; Xingzong Jiang; Ling Du; Chunmei Yang
- Web page: https://patentgrep.com/patent/US12772656B2

## CPC

- H10K 50/131: {with spacer layers between the electroluminescent layers}
- H10K 50/155: comprising dopants
- H10K 50/166: {comprising a multilayered structure}
- H10K 50/19: Tandem OLEDs
- H10K 59/35: comprising red-green-blue [RGB] subpixels
- H10K 2102/351: {Thickness}
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

A display element includes: multiple light-emitting elements, at least one light-emitting element includes an anode layer and a cathode layer arranged opposite to each other, and at least two light-emitting units located between the anode layer and the cathode layer. When an application environment of the display element changes from a normal temperature to a first temperature, a change amount of a horizontal coordinate of a white point of the display element is less than or equal to 0.002, a change amount of a vertical coordinate of the white point of the display element is less than or equal to 0.008, and a color shift value of the display element is less than or equal to 1.4.

## Claims

### Claim 1

A display element comprising: a plurality of light-emitting elements, wherein at least one light-emitting element comprises an anode layer and a cathode layer arranged opposite to each other, and at least two light-emitting units located between the anode layer and the cathode layer;
an N-type charge generation layer and a P-type charge generation layer arranged in a laminated manner between the at least two light-emitting units, wherein the N-type charge generation layer is close to the anode layer and the P-type charge generation layer is close to the cathode layer;
the at least one light-emitting element further comprising:
a light diffusing layer located on a side of the cathode layer away from the at least two light-emitting units, a thickness d1 of the light diffusing layer meeting: 750 Å≤d1≤800 Å; wherein
when an application environment of the display element changes from a normal temperature to a first temperature, a change amount of a horizontal coordinate of a white point of the display element is less than or equal to 0.002, and a change amount of a vertical coordinate of the white point of the display element is less than or equal to 0.008; and a color shift value of the display element is less than or equal to 1.4.

### Claim 2 (depends on 1)

The display element according to claim 1, wherein the plurality of light-emitting elements is divided into a plurality of light-emitting element groups, each light-emitting element group comprises a first light-emitting element, a second light-emitting element and a third light-emitting element with different colors, wherein the first light-emitting element and the second light-emitting element are located in one column along a first direction, and the third light-emitting element is located in another column;
in a same light-emitting element group, a distance L1 between a pixel opening region of the first light-emitting element and a pixel opening region of the third light-emitting element meets: 18 μm≤L1≤22 μm.

### Claim 3 (depends on 1)

The display element according to claim 1, wherein the at least one light-emitting element further comprises a pixel driving circuit coupled to the anode layer, a voltage value of a positive power source signal received by the pixel driving circuit is between 4.5V and 4.7V, a voltage value of an initialization signal received by the pixel driving circuit is between −7.6V and −4.8V, and a voltage value of a negative power source signal received by the cathode layer is between −10V and −6V.

### Claim 4 (depends on 3)

The display element according to claim 3, wherein the display element further comprises a gate driving circuit coupled to the pixel driving circuit and configured to apply a scanning signal to the pixel driving circuit, a voltage value of a direct current (DC) high-level signal received by the gate driving circuit is between 5V and 9V, and a voltage value of a DC low-level signal received by the gate driving circuit is between −13V and −9V.

### Claim 5 (depends on 1)

The display element according to claim 1, wherein when the first temperature is between 25° C. and 85° C., in an environment of the first temperature, the horizontal coordinate of the white point of the display element is between 0.298 and 0.3, and the vertical coordinate of the white point of the display element is between 0.308 and 0.315.

### Claim 6 (depends on 1)

The display element according to claim 1, wherein when the first temperature is between −40° C. and 25° C., in an environment of the first temperature, wherein the horizontal coordinate of the white point of the display element is between 0.296 and 0.3, and the vertical coordinate of the white point of the display element is between 0.327 and 0.339.

### Claim 7 (depends on 1)

The display element according to claim 1, wherein a doping concentration m1 of the P-type charge generation layer meets: 10%≤m1≤15%.

### Claim 8 (depends on 1)

The display element according to claim 1, wherein a doping concentration m2 of the N-type charge generation layer meets: 0.5%≤m2≤1%.

### Claim 9 (depends on 1)

The display element according to claim 1, wherein the at least one light-emitting element further comprises:
a first hole transport layer located between the anode layer and the at least two light-emitting units adjacent to the anode layer, and a doping concentration m3 of the first hole transport layer meeting: 1.0%≤m3≤1.2%.

### Claim 10 (depends on 9)

The display element according to claim 9, wherein each of the P-type charge generation layer and the first hole transport layer is made of at least one of propylene glycol alginate sodium sulfate, nickel oxide, or poly [3-(4-methylamincarboxylbutyl) thiophene].

### Claim 11 (depends on 9)

The display element according to claim 9, wherein the first hole transport layer comprises a second base transport layer and a second doped layer, a thickness d5 of the second base transport layer meeting: 150 Å≤d5≤300 Å, and a thickness d6 of the second doped layer meeting: 95 Å≤d6≤105 Å.

### Claim 12 (depends on 1)

The display element according to claim 1, wherein the N-type charge generation layer is made of at least one of carbon 60 or 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline.

### Claim 13 (depends on 1)

The display element according to claim 1, wherein the light diffusing layer is made of at least one of triarylamines, cyclic ureas, acyl structures or dibenzothiophenes.

### Claim 14 (depends on 1)

The display element according to claim 1, wherein the P-type charge generation layer comprises a first base transport layer and a first doped layer, a thickness d2 of the first base transport layer meeting: 300 Å≤d2≤500 Å, a thickness d3 of the first doped layer meeting: 50 Å≤d3≤200 Å.

### Claim 15 (depends on 1)

The display element according to claim 1, wherein a thickness d4 of the N-type charge generation layer meets: 50 Å≤d4≤250 Å.

### Claim 16 (depends on 9)

The display element according to claim 9, wherein the at least one light-emitting element further comprises:
a first electron transport layer located between the cathode layer and the at least two light-emitting units; and/or
a second electron transport layer located between the N-type charge generation layer and the at least two light-emitting units, and the second electron transport layer located on a side of the N-type charge generation layer away from the P-type charge generation layer; and/or
an electron injection layer located between the cathode layer and the first electron transport layer; and/or
a hole injection layer located between the first hole transport layer and the anode layer; and/or
a second hole transport layer located between the P-type charge generation layer and a light-emitting unit of the at least two light-emitting units, and the second hole transport layer located on a side of the P-type charge generation layer away from the N-type charge generation layer.

### Claim 17 (depends on 9)

The display element according to claim 9, wherein the at least one light-emitting element further comprises:
a first hole blocking layer located between the electron transport layer and the at least two light-emitting units; and/or
at least one second hole blocking layer located on a side of a corresponding N-type charge generation layer facing the anode layer, and the second hole blocking layer located between a corresponding N-type charge generation layer and the at least two light-emitting units adjacent to the N-type charge generation layer.

### Claim 18 (depends on 2)

The display element according to claim 2, wherein the at least two light-emitting units comprises a buffer layer and a light-emitting material layer arranged in a laminated manner, the buffer layer is located between the light-emitting material layer and the anode layer.

### Claim 19 (depends on 18)

The display element according to claim 18, wherein the first light-emitting element comprises a red light-emitting unit, the second light-emitting element comprises a green light-emitting unit, and the third light-emitting element comprises a blue light-emitting unit;
the red light-emitting unit comprises a red buffer layer and a red light-emitting material layer, a thickness d7 of the red buffer layer meets: 100 Å≤d7≤350 Å, a thickness d8 of the red light-emitting material layer meets: 400 Å≤d8≤500 Å, and a doping concentration m4 of the red light-emitting material layer meets: 10%≤m4≤15%;
the green light-emitting unit comprises a green buffer layer and a green light-emitting material layer, a thickness d9 of the green buffer layer meets: 80 Å≤d9≤100 Å, a thickness d10 of the green light-emitting material layer meets: 300 Å≤d10≤500 Å, and a doping concentration m5 of the green light-emitting material layer meets: 8%≤m5≤10%; and
the blue light-emitting unit comprises a blue buffer layer and a blue light-emitting material layer, a thickness d11 of the blue buffer layer meets: 80 Å≤d11≤100 Å, a thickness d12 of the blue light-emitting material layer meets: 150 Å≤d12≤200 Å, and a doping concentration m6 of the blue light-emitting material layer meets: 2%≤m6≤3%.

### Claim 20 (depends on 1)

A display device comprising the display element according to claim 1.