CN-114005860-B - Display substrate, preparation method thereof and display device

CN114005860BCN 114005860 BCN114005860 BCN 114005860BCN-114005860-B

Abstract

The display substrate, the preparation method thereof and the display device can solve the problem of carrier crosstalk among different sub-pixels in the display substrate, effectively improve the gray definition of the display substrate and improve the display effect. The display substrate comprises a substrate base plate and a plurality of sub-pixels arranged on the substrate base plate, wherein each sub-pixel at least comprises one light emitting device, each light emitting device consists of a first electrode layer, a light emitting layer, an organic functional layer and a second electrode layer which are arranged in a containing part of the pixel limiting layer, and an interlayer insulating layer is arranged between the pixel limiting layer and the substrate base plate. The display substrate further comprises a first concave part penetrating through the thicknesses of the pixel limiting layer and the interlayer insulating layer, and the organic functional layer is provided with a first opening at a position corresponding to the first concave part.

Inventors

SU YANXIN
WEI YUE
DENG WEI
DENG LEI
ZOU FUWEI
WANG QIAN
TANG XIA

Assignees

京东方科技集团股份有限公司
成都京东方光电科技有限公司

Dates

Publication Date: 20260512
Application Date: 20211029

Claims (17)

1. A display substrate comprises a substrate, a plurality of sub-pixels arranged on the substrate, wherein each sub-pixel at least comprises a light emitting device, the light emitting device comprises a first electrode layer, a second electrode layer, a light emitting layer and an organic functional layer, the first electrode layer and the second electrode layer are arranged on the substrate, the light emitting layer and the organic functional layer are arranged between the first electrode layer and the second electrode layer, and the organic functional layer of each light emitting device is of an integrated structure, and the display substrate is characterized by further comprising an interlayer insulating layer positioned on one side of the first electrode layer close to the substrate, and a pixel limiting layer positioned on one side of the first electrode layer close to the light emitting layer, wherein a plurality of accommodating parts are formed in the pixel limiting layer, and the orthographic projection of one first electrode layer on the substrate and the orthographic projection of one accommodating part on the substrate are at least partially overlapped; Forming at least a first concave portion penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer between any adjacent sub-pixels; The front projection of the first concave part on the substrate is not overlapped with the front projection of the first electrode layer on the substrate, the front projection of the first concave part on the substrate surrounds a partial area of the front projection of the sub-pixels on the substrate, the caliber of the first concave part along the direction deviating from the substrate is gradually increased, and the side wall of the first concave part is provided with a smooth surface.
2. The display substrate according to claim 1, wherein a length of a first opening between any adjacent sub-pixels is not smaller than a first length, the first length being a maximum width of the adjacent sub-pixels in an extending direction of the first opening.
3. The display substrate according to claim 2, wherein the lengths of the respective first openings are equal, and the first opening length is not smaller than a second length which is a largest one of widths in the extending direction of the first openings in the respective sub-pixels.
4. The display substrate according to claim 1, wherein a plurality of second concave portions penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer portion are further formed between any adjacent sub-pixels; the front projection of the second concave part on the substrate is arranged corresponding to the vertex angle of the front projection of the accommodating part of the pixel limiting layer on the substrate, and the organic functional layer forms a second opening at the corresponding position of the second concave part.
5. The display substrate according to claim 4, wherein the second electrode layer of each light emitting device is an integrally formed structure, and a second opening is formed in a position of the second electrode layer corresponding to the second concave portion in the organic functional layer.
6. The display substrate according to claim 1, wherein the number of first concave portions between the sub-pixels adjacently arranged is plural, and the extending direction of each of the first concave portions is the same.
7. The display substrate according to claim 1, wherein the organic functional layer comprises at least one of a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer.
8. The display substrate according to claim 1, wherein the second electrode layer of each light emitting device is an integrally formed structure, and a first opening is formed in a position of the second electrode layer corresponding to the first concave portion in the organic functional layer.
9. The display substrate according to claim 1, further comprising a defining portion located on both sides of the first concave portion and arranged in a same layer along the first electrode layer, wherein a material of the defining portion is the same as a material of the first electrode layer.
10. The display substrate according to claim 1, wherein each of the sub-pixels further comprises a pixel driving circuit including a thin film transistor, the display substrate further comprising a buffer layer between an active layer of the thin film transistor and the substrate, a gate insulating layer between a layer where a gate electrode of the thin film transistor is located and the active layer, a first insulating layer between the layer where the gate electrode of the thin film transistor is located and the layers where source and drain electrodes of the thin film transistor are located, a planarization layer between the layers where the source and drain electrodes of the thin film transistor are located and the first electrode layer, and a drain electrode of the thin film transistor is electrically connected to the first electrode layer through a via hole penetrating the planarization layer; the interlayer insulating layer includes the buffer layer, the gate insulating layer, the first insulating layer, and the planarization layer, and the first concave portion penetrates at least one of the buffer layer, the first insulating layer, and the planarization layer.
11. The display substrate of claim 10, wherein the first recess extends through a portion of a thickness of the planarization layer.
12. The display substrate of claim 11, wherein the first recess has a depth ranging from 1200 a to 2000 a.
13. The display substrate according to claim 12, wherein the plurality of sub-pixels includes red sub-pixels, first green sub-pixels, second green sub-pixels, and blue sub-pixels, wherein the plurality of first green sub-pixels and the plurality of second green sub-pixels are alternately arranged at intervals in a first direction to form a first pixel row, the plurality of red sub-pixels and the plurality of blue sub-pixels are alternately arranged at intervals in the first direction to form a second pixel row, the plurality of first pixel row and the plurality of second pixel row are alternately arranged at intervals in the second direction, and the plurality of first green sub-pixels and the plurality of second green sub-pixels are alternately arranged at intervals in the second direction to form a first pixel column, the plurality of red sub-pixels and the plurality of blue sub-pixels are alternately arranged at intervals in the first direction to form a second pixel column, and the plurality of first pixel columns and the plurality of second pixels are alternately arranged at intervals in the first direction.
14. A preparation method of a display substrate comprises the steps of forming a substrate and a plurality of sub-pixels arranged on the substrate, wherein each sub-pixel at least comprises a light emitting device, the process of forming the light emitting device comprises the steps of sequentially forming a first electrode layer, a second electrode layer, a light emitting layer and an organic functional layer which are arranged between the first electrode layer and the second electrode layer on the substrate, and the organic functional layers of the light emitting devices are of an integrated structure, and the method is characterized in that an interlayer insulating layer is formed on one side, close to the substrate, of the first electrode layer, a pixel limiting layer is formed on one side, close to the light emitting layer, of the first electrode layer, and a plurality of accommodating parts are formed in the pixel limiting layer, and the orthographic projection of one first electrode layer on the substrate and the orthographic projection of one accommodating part on the substrate are at least partially overlapped; forming a first concave portion penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer portion between any adjacent sub-pixels; The front projection of the first concave part on the substrate is not overlapped with the front projection of the first electrode layer on the substrate, the front projection of the first concave part on the substrate surrounds a partial area of the front projection of the sub-pixels on the substrate, the caliber of the first concave part along the direction deviating from the substrate is gradually increased, and the side wall of the first concave part is provided with a smooth surface.
15. The method according to claim 14, further comprising forming two first concave portions extending in the same direction and penetrating the thicknesses of the pixel defining layer and the interlayer insulating layer portion between any adjacent sub-pixels, and forming the first openings at positions corresponding to the first concave portions in the organic functional layer.
16. The method according to claim 15, further comprising forming a plurality of second concave portions penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer portion between any adjacent sub-pixels; the front projection of the second concave part on the substrate is arranged corresponding to the vertex angle of the front projection of the accommodating part of the pixel limiting layer on the substrate, and the organic functional layer forms a second opening at the corresponding position of the second concave part.
17. A display device comprising the display substrate of any one of claims 1-13.

Description

Display substrate, preparation method thereof and display device Technical Field The disclosure belongs to the technical field of display, and particularly relates to a display substrate, a preparation method thereof and a display device. Background An Organic LIGHT EMITTING Diode (OLED) display panel has many advantages of self-luminescence, low driving voltage, high luminous efficiency, short response time, high definition and contrast, wide viewing angle, wide use temperature range, large-area full color display, and the like, and is known as the display panel with the most development potential in the industry. An OLED display panel belongs to a self-luminous type display panel, and an OLED light emitting device thereon generally includes pixel electrodes respectively used as anodes (Anode), a common electrode used as a cathode (cathode), and organic functional layers disposed between the pixel electrodes and the common electrode, which emit light when a current is passed therethrough. However, in practice, the applicant finds that at present, the OLED device generally has a crosstalk problem between different sub-pixels, that is, carriers can enter adjacent sub-pixels through an electron transport layer or a hole transport layer in an organic functional layer to cause the adjacent sub-pixels to emit light, so that the gray scale definition of the display device is reduced, and the display effect of the device is affected. Disclosure of Invention The present disclosure aims to adopt the following technical solutions. In a first aspect, an embodiment of the disclosure provides a display substrate, which comprises a substrate, a plurality of sub-pixels arranged on the substrate, wherein each sub-pixel comprises at least a light emitting device, the light emitting device comprises a first electrode layer, a second electrode layer and a light emitting layer and an organic functional layer which are arranged on the substrate, the organic functional layer of each light emitting device is of an integrated structure, the display substrate further comprises an interlayer insulating layer positioned on one side of the first electrode layer close to the substrate, and a pixel limiting layer positioned on one side of the first electrode layer close to the light emitting layer, a plurality of accommodating parts are formed in the pixel limiting layer, and the orthographic projection of one first electrode layer on the substrate and the orthographic projection of one accommodating part on the substrate are at least partially overlapped; At least a first concave portion penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer is formed between any adjacent sub-pixels, and a first opening is formed in the organic functional layer at a position corresponding to the first concave portion. The length of the first opening between any two adjacent sub-pixels is not smaller than a first length, and the first length is the maximum width of the adjacent sub-pixels in the extending direction of the first opening. The lengths of the first openings are equal, and the length of the first opening is not smaller than a second length, wherein the second length is the largest one of the widths of the sub-pixels in the extending direction of the first opening. Wherein a plurality of second concave portions penetrating through the thicknesses of the pixel defining layer and the interlayer insulating layer portion are further formed between any adjacent sub-pixels; the front projection of the second concave part on the substrate is arranged corresponding to the vertex angle of the front projection of the accommodating part of the pixel limiting layer on the substrate, and the organic functional layer forms a second opening at the corresponding position of the second concave part. The second electrode layers of the light emitting devices are of an integrated structure, and a second opening is formed in the position, corresponding to the second concave portion, of the second electrode layers and the organic functional layers. The number of the first concave parts between the adjacent sub-pixels is a plurality of the first concave parts, and the extending directions of the first concave parts are the same. Wherein the organic functional layer comprises at least one of a hole transport layer, a hole injection layer, an electron transport layer and an electron injection layer. The second electrode layers of the light emitting devices are of an integrated structure, and a first opening is formed in the position, corresponding to the first concave part, of the second electrode layers and the organic functional layers. The display panel further comprises limiting parts which are positioned on two sides of the first concave part and are arranged along the same layer of the first electrode layer, and the material of the limiting parts is the same as that of the first electrode layer. Wherein each sub-pixe