Display substrate, preparation method thereof and display device

1. A display substrate, comprising a display region and an opening region, the display region surrounding the opening region,

wherein a first barrier wall is between the display region and the opening region, and the first barrier wall surrounds the opening region;

the first barrier wall comprises a first metal layer structure, and at least one side surface, surrounding the opening region, of the first metal layer structure comprises a recess;

the display substrate further comprises a base substrate,

the first metal layer structure comprises:

a first metal sub-layer on a first side of the base substrate, and

a second metal sub-layer on a side of the first metal sub-layer away from the base substrate,

wherein an orthographic projection of the first metal sub-layer on the base substrate is within an orthographic projection of the second metal sub-layer on the base substrate, so as to form the recess.

2. The display substrate according to claim 1 , wherein the display region comprises an electrode pattern,

the electrode pattern comprises a second metal layer structure, the first metal layer structure and the second metal layer structure have a same structure and comprise a same material.

3. The display substrate according to claim 1 , wherein the first metal layer structure further comprises a third metal sub-layer on the first side of the base substrate,

the first metal sub-layer is on a side of the third metal sub-layer away from the base substrate, and the orthographic projection of the first metal sub-layer on the base substrate is within an orthographic projection of the third metal sub-layer on the base substrate; and

the orthographic projection of the second metal sub-layer on the base substrate is within the orthographic projection of the third metal sub-layer on the base substrate.

4. The display substrate according to claim 3 , wherein a thickness of the first metal sub-layer is larger than a thickness of the second metal sub-layer and is larger than a thickness of the third metal sub-layer; and

the thickness of the first metal sub-layer ranges from 150 nm to 900 nm, the thickness of the second metal sub-layer ranges from 30 nm to 300 nm, and the thickness of the third metal sub-layer ranges from 30 nm to 300 nm.

5. The display substrate according to claim 1 , wherein an indentation direction of the recess is parallel to the base substrate.

6. The display substrate according to claim 1 , further comprising a second barrier wall that is between the display region and the opening region,

wherein the second barrier wall surrounds the opening region, has a same structure as the first barrier wall, and is arranged on a side of the first barrier wall away from the opening region.

7. The display substrate according to claim 1 , wherein the display region further comprises a first electrode layer, a second electrode layer, and an organic functional layer between the first electrode layer and the second electrode layer,

the first electrode layer, the second electrode layer, and the organic functional layer are configured to form a light emitting device; and the organic functional layer is disconnected at the side surface, comprising the recess, of the first barrier wall;

the second electrode layer is a cathode layer, and the cathode layer is disconnected at the side surface, comprising the recess, of the first barrier wall.

8. The display substrate according to claim 1 , further comprising a sensor,

wherein the sensor is connected to the base substrate, and an orthographic projection of the sensor on the base substrate at least partially overlaps with the opening region.

9. The display substrate according to claim 1 , wherein under action of an etching solution for etching to form the first metal layer structure, an etching rate of a material of the first metal sub-layer is larger than an etching rate of a material of the second metal sub-layer;

the material of the first metal sub-layer comprises aluminum or copper; and the material of the second metal sub-layer comprises titanium or molybdenum.

10. The display substrate according to claim 1 , wherein the first barrier wall further comprises an insulation layer structure,

the insulation layer structure is on the first side of the base substrate, and the first metal layer structure is on a side of the insulation layer structure away from the base substrate; and

the insulation layer structure comprises a plurality of insulation sub-layers.

11. A display device, comprising the display substrate according to claim 1 .

12. A preparation method of a display substrate, comprising:

forming a display region and an opening region, wherein the display region surrounds the opening region, and

forming a first barrier wall between the display region and the opening region, wherein the first barrier wall surrounds the opening region and comprises a first metal layer structure, and a recess is formed on at least one side surface, surrounding the opening region, of the first metal layer structure;

wherein the preparation method further comprises: providing a base substrate,

the first metal layer structure comprises:

a first metal sub-layer on a first side of the base substrate, and

a second metal sub-layer on a side of the first metal sub-layer away from the base substrate,

wherein an orthographic projection of the first metal sub-layer on the base substrate is within an orthographic projection of the second metal sub-layer on the base substrate, so as to form the recess.

13. The preparation method according to claim 12 , wherein the opening region is formed by laser cutting or mechanical punching.

14. The preparation method of claim 12 , wherein forming the display region comprises:

forming an electrode pattern when forming the first metal layer structure,

wherein the electrode pattern comprises a second metal layer structure, and the first metal layer structure and the second metal layer structure are formed using a same layer.

15. The preparation method of claim 14 , wherein forming the first barrier wall comprises:

forming a first metal material layer on a first side of the base substrate, and forming a second metal material layer on a side of the first metal material layer away from the base substrate;

performing a first etching process on the first metal material layer and the second metal material layer to form the electrode pattern and an initial barrier wall; and

performing a second etching process on the initial barrier wall to form the first barrier wall, wherein a wet etching method is adopted in the second etching process, and an etching rate produced by an etching solution used in the second etching process on the first metal material layer is larger than an etching rate produced by the etching solution on the second metal material layer, so that the recess is formed.

16. The preparation method of claim 14 , wherein forming the first barrier wall comprises:

sequentially forming a third metal material layer, a first metal material layer and a second metal material layer on a first side of the base substrate;

performing a first etching process on the third metal material layer, the first metal material layer and the second metal material layer to form the electrode pattern and an initial barrier wall; and

performing a second etching process on the initial barrier wall to form the first barrier wall, wherein a wet etching method is adopted in the second etching process, and an etching rate produced by an etching solution used in the second etching process on the first metal material layer is larger than an etching rate produced by the etching solution on the second metal material layer and is larger than an etching rate produced by the etching solution on the third metal material layer, so that the recess is formed.

17. The preparation method according to claim 15 , wherein the first etching process adopts a dry etching method.

18. The preparation method according to claim 15 , wherein forming the display region further comprises:

forming a first electrode layer, a second electrode layer, and an organic functional layer between the first electrode layer and the second electrode layer,

wherein the first electrode layer, the second electrode layer, and the organic functional layer are configured to form a light emitting device,

the etching solution used in the second etching process is same as an etching solution used for etching to form the first electrode layer, and the organic functional layer is disconnected at the side surface, comprising the recess, of the first barrier wall.

19. The preparation method of claim 14 , wherein forming the first barrier wall comprises:

forming a first metal material layer on a first side of the base substrate;

forming a second metal material layer on a side of the first metal material layer away from the base substrate; and

performing one wet etching process on the first metal material layer and the second metal material layer, wherein an etching rate produced by an etching solution used in the wet etching process on the first metal material layer is larger than an etching rate produced by the etching solution on the second metal material layer.