CN-122003020-A - Light emitting device, manufacturing method thereof, display panel and electronic equipment

Abstract

The application provides a light emitting device, a preparation method thereof, a display panel and electronic equipment, and relates to OLED display technology. The light emitting device includes a hole transport layer, a light emitting layer, and a confinement layer. The light emitting layer includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer. The confinement layer is located between the light-emitting layer and the hole transport layer. The HOMO level of the confinement layer is greater than the HOMO level of the red light-emitting layer and the HOMO level of the confinement layer is greater than the HOMO level of the green light-emitting layer. The limiting layer plays a role in improving the starting voltage of the red-green light-emitting layer and reducing crosstalk.

Inventors

• KONG CHAO
• WU LIJIE
• YIN HAN
• LUO XINTAO
• HU YUNSONG

Assignees

• 华为技术有限公司

Dates

Publication Date

20260508

Application Date

20241108

Claims (16)

1. 1. A light-emitting device, characterized in that the light-emitting device comprises a hole transport layer, a light-emitting layer and a confinement layer; the light-emitting layer and the hole transport layer are laminated, and the light-emitting layer comprises a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer; In the lamination direction of the light emitting layer and the hole transport layer, the confinement layer is located between the red light emitting layer and the hole transport layer, the confinement layer is located between the green light emitting layer and the hole transport layer, the absolute value of the HOMO level of the confinement layer is greater than the absolute value of the HOMO level of the red light emitting layer, and the absolute value of the HOMO level of the confinement layer is greater than the absolute value of the HOMO level of the green light emitting layer.
2. 2. The light-emitting device according to claim 1, wherein a T1 energy level of the confinement layer is greater than or equal to a T1 energy level of the blue light-emitting layer, and wherein an S1 energy level of the confinement layer is greater than or equal to an S1 energy level of the blue light-emitting layer.
3. 3. The light-emitting device according to claim 2, wherein the T1 level range of the confinement layer is [1.6ev,2.1ev ].
4. 4. The light-emitting device according to claim 2, wherein the S1 level range of the confinement layer is [2.8ev,3.2ev ].
5. 5. The light-emitting device according to any one of claims 1 to 4, wherein the HOMO level range of the confinement layer is [ -5.5eV, -6.0eV ].
6. 6. The light-emitting device according to any one of claims 1 to 5, wherein a material of the confinement layer is the same as a material of the blue light-emitting layer.
7. 7. The light-emitting device according to any one of claims 1 to 6, wherein the blue light-emitting layer comprises a host material and a guest material, and wherein the confinement layer comprises the same host material as the blue light-emitting layer.
8. 8. The light-emitting device according to any one of claims 1 to 7, further comprising an auxiliary light-emitting layer comprising a red auxiliary layer and a green auxiliary layer; In the lamination direction, the red auxiliary layer is located between the red light emitting layer and the confinement layer, the green auxiliary layer is located between the green light emitting layer and the confinement layer, and the confinement layer is in contact with the blue light emitting layer.
9. 9. The light-emitting device according to any one of claims 1 to 7, further comprising an auxiliary light-emitting layer comprising a red auxiliary layer, a green auxiliary layer, and a blue auxiliary layer; in the lamination direction, the red auxiliary layer is located between the red light emitting layer and the confinement layer, the green auxiliary layer is located between the green light emitting layer and the confinement layer, and the blue auxiliary layer is located between the blue light emitting layer and the confinement layer or between the confinement layer and the hole transport layer.
10. 10. A light-emitting device according to any one of claims 1-8, wherein the thickness of the confinement layer is in the range [5nm,40nm ].
11. 11. A method for manufacturing a light emitting device, characterized in that the method comprises, Forming a confinement layer on the hole transport layer; And forming a light-emitting layer on one side of the limiting layer, which is far away from the hole transport layer, wherein the light-emitting layer comprises a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer, the absolute value of the HOMO energy level of the limiting layer is larger than that of the red light-emitting layer, and the absolute value of the HOMO energy level of the limiting layer is larger than that of the green light-emitting layer.
12. 12. The method according to claim 11, wherein the T1 energy level of the confinement layer is greater than or equal to the T1 energy level of the blue light-emitting layer, and the S1 energy level of the confinement layer is greater than or equal to the S1 energy level of the blue light-emitting layer.
13. 13. The method of manufacturing according to claim 11, further comprising: forming an auxiliary light emitting layer on one side of the limiting layer away from the hole transport layer, wherein the auxiliary light emitting layer comprises a red auxiliary layer, a green auxiliary layer and a blue auxiliary layer; the light-emitting layer is formed on one side of the limiting layer, which is away from the hole transport layer, and the light-emitting layer is formed on one side of the auxiliary light-emitting layer, which is away from the hole transport layer, so that the red auxiliary layer is located between the red light-emitting layer and the limiting layer, the green auxiliary layer is located between the green light-emitting layer and the limiting layer, and the blue auxiliary layer is located between the blue light-emitting layer and the limiting layer.
14. 14. The method of claim 11, wherein prior to forming the confinement layer on the hole transport layer, the method further comprises forming a blue assist layer on the hole transport layer; forming a limiting layer on the hole transport layer, wherein the limiting layer is formed on one side of the hole transport layer and the blue auxiliary layer, which is away from the hole transport layer; The preparation method further comprises forming a red auxiliary layer and a green auxiliary layer on one side of the limiting layer away from the hole transport layer; Forming a light-emitting layer on a side of the confinement layer facing away from the hole transport layer, including: Forming the red light emitting layer on a side of the red auxiliary layer facing away from the hole transporting layer such that the red auxiliary layer is located between the red light emitting layer and the confinement layer, Forming the green light-emitting layer on a side of the green auxiliary layer facing away from the hole transport layer such that the green auxiliary layer is located between the green light-emitting layer and the confinement layer, And forming the blue light-emitting layer on one side of the limiting layer, which is away from the blue auxiliary layer, so that the blue auxiliary layer is positioned between the limiting layer and the hole transport layer.
15. 15. A display panel, characterized in that the display panel comprises a substrate and a light emitting device according to any one of claims 1-9, which is provided on the substrate.
16. 16. An electronic device comprising a housing and the display panel of claim 15, wherein the display panel is disposed on the housing.

Description

Light emitting device, manufacturing method thereof, display panel and electronic equipment Technical Field The present application relates to the field of display technologies, and in particular, to a light emitting device, a manufacturing method thereof, a display panel, and an electronic apparatus. Background At present, an Organic Light-Emitting Diode (OLED) has been widely used in life of people, for example, on terminal display screens of mobile phones, tablets, computers and the like, and has remarkable advantages of high brightness, bright color, high contrast ratio and the like. The organic light emitting device includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer, which can emit light alone to provide a color picture. However, the on-voltage of the red light emitting layer and the green light emitting layer is lower than that of the blue light emitting layer. When the application scene of the blue light-emitting layer is required to be lightened, the current can lighten the red and green light-emitting layers through the common layers such as the hole transmission layer and the like to cause crosstalk, so that the light color is impure. Disclosure of Invention The embodiment of the application provides a light emitting device, a preparation method thereof, a display panel and electronic equipment, which can reduce red-green crosstalk and improve light color purity when a blue light emitting layer is lightened. In a first aspect, an embodiment of the present application provides a light emitting device including a hole transporting layer, a light emitting layer, and a confinement layer. The hole transport layer is laminated with the light emitting layer. The light emitting layer includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer. In the lamination direction of the hole transport layer and the light emitting layer, the confinement layer is located between the red light emitting layer and the hole transport layer, and the confinement layer is located between the green light emitting layer and the hole transport layer. The absolute value of the HOMO level of the confinement layer is greater than the absolute value of the HOMO level of the red light emitting layer, and the absolute value of the HOMO level of the confinement layer is greater than the absolute value of the HOMO level of the green light emitting layer. According to the light-emitting device provided by the application, as the absolute value of the HOMO energy level of the limiting layer is larger than that of the red light-emitting layer and the HOMO energy level of the green light-emitting layer between the red light-emitting layer and the hole-transporting layer and between the green light-emitting layer and the hole-transporting layer, the HOMO energy level of the limiting layer is deeper than that of the red light-emitting layer and the green light-emitting layer, namely, a hole injection barrier is added between the red light-emitting layer and the hole-transporting layer and between the red light-emitting layer and the hole-transporting layer, so that after the hole reaches the hole-transporting layer, a higher voltage is needed to be injected into the red light-emitting layer and the green light-emitting layer across the limiting layer. Therefore, when the blue light-emitting layer is lightened, the newly added limiting layer plays a role in preventing hole injection of the hole transmission layer to the red light-emitting layer and the green light-emitting layer, the limiting layer plays a role in improving the starting voltage of the red light-emitting layer and the green light-emitting layer, and is beneficial to reducing the influence of red-green light crosstalk and blue light, so that the purity of light color is improved. In one possible implementation manner, according to the first aspect, the T1 energy level of the confinement layer is greater than or equal to the T1 energy level of the blue light emitting layer, and the S1 energy level of the confinement layer is greater than or equal to the S1 energy level of the blue light emitting layer. In this possible implementation manner, the T1 energy level of the confinement layer is greater than or equal to the T1 energy level of the blue light-emitting layer, and the S1 energy level of the confinement layer is greater than or equal to the S1 energy level of the blue light-emitting layer, which is favorable for restricting photons of the blue light-emitting layer, reducing the possibility that photons of the blue light-emitting layer transit to the confinement layer, that is, reducing the possibility that energy is turned from the blue light-emitting layer to the confinement layer, thereby improving the light-emitting efficiency of the blue light-emitting layer while reducing color crosstalk caused by the red light-emitting layer and the green light-emitting layer to the bright blue li