Display panel, manufacturing method thereof and display device

1. A display panel, comprising a base substrate, a thin film transistor (TFT) array arranged on the base substrate, a pixel definition layer arranged at a side of the TFT array away from the base substrate, and a plurality of light-emitting units arranged at a pixel region defined by the pixel definition layer, wherein the display panel further comprises a plurality of spacers arranged on a surface of the pixel definition layer away from the base substrate, a surface of at least one spacer away from the base substrate comprises a first portion and a second portion, a distance between the second portion and the base substrate is smaller than a distance between the first portion and the base substrate; wherein a slope angle of the pixel definition layer is not larger than 30°, and a slope angle of each spacer is not smaller than 40°.

2. The display panel according to claim 1 , wherein the plurality of spacers is formed integrally with the pixel definition layer.

3. The display panel according to claim 2 , wherein the plurality of spacers is uniformly distributed on the base substrate.

4. The display panel according to claim 1 , wherein the second portion forms a groove.

5. The display panel according to claim 4 , wherein the plurality of spacers is uniformly distributed on the base substrate.

6. The display panel according to claim 1 , wherein a ratio of an area of the second portion to an area of the first portion is about 0.5 to 1.

7. The display panel according to claim 6 , wherein the plurality of spacers is uniformly distributed on the base substrate.

8. The display panel according to claim 1 , wherein a ratio of a height of each spacer to a height of the pixel definition layer is about 2 to 2.5, the height of each spacer is a maximum distance between the surface of the spacer away from the base substrate and the base substrate, and the height of the pixel definition layer is a maximum distance between the surface of the pixel definition layer away from the base substrate and the base substrate.

9. The display panel according to claim 8 , wherein the plurality of spacers is uniformly distributed on the base substrate.

10. The display panel according to claim 1 , wherein the plurality of spacers is uniformly distributed on the base substrate.

11. The display panel according to claim 1 , wherein a ratio of a sum of areas of the first portions of the plurality of spacers to an area of a display region of the display panel is not smaller than a preset threshold and the preset threshold is about 0.5% to 2.5%.

12. The display panel according to claim 11 , wherein the preset threshold is about 1.5%.

13. A display device, comprising the display panel according to claim 1 .

14. A method for manufacturing a display panel, comprising:

forming a TFT array on a base substrate;

forming a pixel definition layer and a plurality of spacers on the pixel definition layer through a single patterning process, a surface of each spacer away from the base substrate comprising a first portion and a second portion, a distance between the second portion and the base substrate being smaller than a distance between the first portion and the base substrate; and

forming a plurality of light-emitting units at a pixel region defined by the pixel definition layer;

wherein a slope angle of the pixel definition layer is not larger than 30°, and a slope angle of each spacer is not smaller than 40°.

15. The method according to claim 14 , wherein a ratio of an area of the second portion to an area of the first portion is about 0.5 to 1.

16. The method according to claim 15 , wherein the pixel definition layer comprises a portion covered by the spacers and a portion not covered by the spacers, wherein the forming the pixel definition layer and the plurality of spacers on the pixel definition layer through a single patterning process comprises:

forming a layer of photoresist for forming the pixel definition layer and the plurality of spacers on the base substrate;

exposing the photoresist through a mask, the mask comprising a first pattern corresponding to the portion not covered by the spacers and a second pattern corresponding to the portion covered by the spacers, the first pattern surrounding the second pattern, the first pattern comprising an opaque pattern and a third partially-transparent pattern, the second pattern comprising a first partially-transparent pattern and a second partially-transparent pattern surrounding the first partially-transparent pattern, a light transmittance of the second partially-transparent pattern being greater than a light transmittance of the first partially-transparent pattern, and the light transmittance of the second partially-transparent pattern being greater than a light transmittance of the third partially-transparent pattern; and

performing a development process to form the pixel definition layer and the plurality of spacers.

17. The method according to claim 16 , wherein the light transmittance of the first partially-transparent pattern gradually decreases in a direction away from the second partially-transparent pattern.

18. The method according to claim 16 , wherein a light transmittance of the first pattern is about 20% to 25%, and a difference between the light transmittance of the second partially-transparent pattern and the light transmittance of the first pattern is greater than 5%.

19. The method according to claim 14 , wherein a ratio of a sum of areas of the first portions of the plurality of spacers to an area of a display region of the display panel is not smaller than a preset threshold and the preset threshold is about 0.5% to 2.5%.

20. The method according to claim 19 , wherein the preset threshold is about 1.5%.