Display substrate, display panel, and manufacturing method of display substrate

1. A display substrate, comprising: a base substrate, a first electrode, a light-emitting functional layer, and a second electrode,

wherein the first electrode is on the base substrate, the light-emitting functional layer is on a side of the first electrode away from the base substrate, the second electrode is on a side of the light-emitting functional layer away from the first electrode, and the first electrode, the light-emitting functional layer, and the second electrode constitute a light-emitting element;

the light-emitting functional layer comprises a first functional layer and a second functional layer on a side of the first functional layer away from the base substrate, an orthographic projection of an edge of the second functional layer on the base substrate is within an orthographic projection of an edge of the first functional layer on the base substrate, and an area of an orthographic projection of the second functional layer on the base substrate is smaller than an area of an orthographic projection of the first functional layer on the base substrate; and

the second electrode covers at least one side surface of the light-emitting functional layer and a portion of a surface of the light-emitting functional layer away from the base substrate, and the second electrode is in contact with the at least one side surface of the light-emitting functional layer and the portion of the surface of the light-emitting functional layer away from the base substrate;

the display substrate comprises a display region and a peripheral region around the display region,

the display substrate further comprises an auxiliary electrode in the peripheral region, the auxiliary electrode is in contact with a side surface of the first functional layer,

the display region comprises a plurality of pixels which are not separated by the peripheral region, an edge of the first functional layer in the peripheral region is closer to the auxiliary electrode than an edge of the second functional layer in the peripheral region.

2. The display substrate according to claim 1 , wherein a surface of the first functional layer away from the base substrate comprises a portion covered by the second functional layer, and

a portion of the surface of the first functional layer away from the base substrate except for the portion covered by the second functional layer is in contact with the second electrode.

3. The display substrate according to claim 2 , wherein an outline of the orthographic projection of the first functional layer on the base substrate is approximately identical to an outline of the orthographic projection of the second functional layer on the base substrate.

4. The display substrate according to claim 2 , wherein a center of the orthographic projection of the first functional layer on the base substrate substantially coincides with a center of the orthographic projection of the second functional layer on the base substrate.

5. The display substrate according to claim 2 , wherein a portion of the second electrode covering the at least one side surface of the light-emitting functional layer has a component extending laterally along a surface of the base substrate.

6. The display substrate according to claim 2 , wherein the first functional layer is in contact with the second functional layer,

the surface of the first functional layer away from the base substrate comprises a portion in contact with the second functional layer and the portion in contact with the second electrode, a side surface of the first functional layer, the portion in contact with the second electrode of the surface of the first functional layer away from the base substrate, and a side surface of the second functional layer are in contact with each other and form a first step structure on the at least one side surface of the light-emitting functional layer, and

the second electrode covers the first step structure and is in contact with the first step structure.

7. The display substrate according to claim 6 , wherein the light-emitting functional layer further comprises a third functional layer on a side of the second functional layer away from the base substrate,

an orthographic projection of an edge of the third functional layer on the base substrate is within the orthographic projection of the edge of the second functional layer on the base substrate, and an area of an orthographic projection of the third functional layer on the base substrate is smaller than the area of the orthographic projection of the second functional layer on the base substrate.

8. The display substrate according to claim 7 , wherein the second functional layer is in contact with the third functional layer,

a surface of the second functional layer away from the base substrate comprises a portion in contact with the third functional layer and a portion in contact with the second electrode,

the side surface of the second functional layer, the portion in contact with the second electrode of the surface of the second functional layer away from the base substrate, and a side surface of the third functional layer are in contact with each other and form a second step structure on the at least one side surface of the light-emitting functional layer, and

the second electrode covers the second step structure and is in contact with the second step structure.

9. The display substrate according to claim 8 , wherein a portion of the second electrode covering the first step structure and a portion of the second electrode covering the second step structure provide a first ladder structure on the at least one side surface of the light-emitting functional layer.

10. The display substrate according to claim 9 , wherein the light-emitting functional layer further comprises a fourth functional layer on a side of the third functional layer away from the base substrate,

an orthographic projection of an edge of the fourth functional layer on the base substrate is within the orthographic projection of the edge of the third functional layer on the base substrate, and an area of an orthographic projection of the fourth functional layer on the base substrate is smaller than the area of the orthographic projection of the third functional layer on the base substrate.

11. The display substrate according to claim 10 , wherein the third functional layer is in contact with the fourth functional layer,

a surface of the third functional layer away from the base substrate comprises a portion in contact with the fourth functional layer and a portion in contact with the second electrode,

the side surface of the third functional layer, the portion in contact with the second electrode of the surface of the third functional layer away from the base substrate, and a side surface of the fourth functional layer are in contact with each other and form a third step structure on the at least one side surface of the light-emitting functional layer, and

the second electrode covers the third step structure and is in contact with the third step structure.

12. The display substrate according to claim 11 , wherein the portion of the second electrode covering the second step structure and a portion of the second electrode covering the third step structure provide a second ladder structure on the at least one side surface of the light-emitting functional layer.

13. The display substrate according to claim 12 , wherein the light-emitting functional layer further comprises a fifth functional layer on a side of the fourth functional layer away from the base substrate,

an orthographic projection of an edge of the fifth functional layer on the base substrate is within the orthographic projection of the edge of the fourth functional layer on the base substrate, and an area of an orthographic projection of the fifth functional layer on the base substrate is smaller than the area of the orthographic projection of the fourth functional layer on the base substrate.

14. The display substrate according to claim 13 , wherein the fourth functional layer is in contact with the fifth functional layer,

a surface of the fourth functional layer away from the base substrate comprises a portion in contact with the fifth functional layer and a portion in contact with the second electrode,

the side surface of the fourth functional layer, the portion in contact with the second electrode of the surface of the fourth functional layer away from the base substrate, and a side surface of the fifth functional layer are in contact with each other and form a fourth step structure on the at least one side surface of the light-emitting functional layer, and

the second electrode covers the fourth step structure and is in contact with the fourth step structure.

15. The display substrate according to claim 14 , wherein the portion of the second electrode covering the third step structure and a portion of the second electrode covering the fourth step structure provide a third ladder structure on the at least one side surface of the light-emitting functional layer.

16. The display substrate according to claim 13 , wherein the first functional layer is a hole injection layer, the second functional layer is a hole transport layer, the third functional layer is a light-emitting layer, the fourth functional layer is an electron transport layer, and the fifth functional layer is an electron injection layer.

17. The display substrate according to claim 2 , wherein

the auxiliary electrode is at least partially around the display region,

the first electrode is in the display region, and

the second electrode is in the display region and the peripheral region, and is electrically connected to the auxiliary electrode through a via hole or by direct contact in the peripheral region.

18. A display panel, comprising the display substrate of claim 1 , wherein the display substrate comprises a base substrate, a first electrode, a light-emitting functional layer, and a second electrode;

the first electrode is on the base substrate, the light-emitting functional layer is on a side of the first electrode away from the base substrate, the second electrode is on a side of the light-emitting functional layer away from the first electrode, and the first electrode, the light-emitting functional layer, and the second electrode constitute a light-emitting element;

the light-emitting functional layer comprises a first functional layer and a second functional layer on a side of the first functional layer away from the base substrate, an orthographic projection of an edge of the second functional layer on the base substrate is within an orthographic projection of an edge of the first functional layer on the base substrate, and an area of an orthographic projection of the second functional layer on the base substrate is smaller than an area of an orthographic projection of the first functional layer on the base substrate; and

the second electrode covers at least one side surface of the light-emitting functional layer and a portion of a surface of the light-emitting functional layer away from the base substrate, and the second electrode is in contact with the at least one side surface of the light-emitting functional layer and the portion of the surface of the light-emitting functional layer away from the base substrate;

the display substrate comprises a display region and a peripheral region around the display region,

the display substrate further comprises an auxiliary electrode in the peripheral region, the auxiliary electrode is in contact with a side surface of the first functional layer,

the display region comprises a plurality of pixels which are not separated by the peripheral region, the edge of the first functional in the peripheral region is closer to the auxiliary electrode than the edge of the second functional layer.

19. A manufacturing method of a display substrate, comprising:

providing a base substrate;

forming a first electrode on the base substrate;

forming a light-emitting functional layer on the first electrode; and

forming a second electrode on the light-emitting functional layer,

wherein the first electrode, the light-emitting functional layer, and the second electrode constitute a light-emitting element,

the light-emitting functional layer comprises a first functional layer and a second functional layer on a side of the first functional layer away from the base substrate, an orthographic projection of an edge of the second functional layer on the base substrate is within an orthographic projection of an edge of the first functional layer on the base substrate, and an area of an orthographic projection of the second functional layer on the base substrate is smaller than an area of an orthographic projection of the first functional layer on the base substrate; and

the second electrode covers at least one side surface of the light-emitting functional layer and a portion of a surface of the light-emitting functional layer away from the base substrate, and the second electrode is in contact with the at least one side surface of the light-emitting functional layer and the portion of the surface of the light-emitting functional layer away from the base substrate;

the display substrate comprises a display region and a peripheral region around the display region,

the display substrate further comprises an auxiliary electrode in the peripheral region, the auxiliary electrode is in contact with a side surface of the first functional layer,

the display region comprises a plurality of pixels which are not separated by the peripheral region, the edge of the first functional layer in the peripheral region is closer to the auxiliary electrode than the edge of the second functional layer.

20. A display substrate, comprising: a base substrate, a first electrode, a light-emitting functional layer, and a second electrode,

wherein the first electrode is on the base substrate, the light-emitting functional layer is on a side of the first electrode away from the base substrate, the second electrode is on a side of the light-emitting functional layer away from the first electrode, and the first electrode, the light-emitting functional layer, and the second electrode constitute a light-emitting element;

the light-emitting functional layer comprises a first functional layer and a second functional layer on a side of the first functional layer away from the base substrate, an orthographic projection of an edge of the second functional layer on the base substrate is within an orthographic projection of an edge of the first functional layer on the base substrate, and an area of an orthographic projection of the second functional layer on the base substrate is smaller than an area of an orthographic projection of the first functional layer on the base substrate; and

the second electrode covers at least one side surface of the light-emitting functional layer and a portion of a surface of the light-emitting functional layer away from the base substrate, and the second electrode is in contact with the at least one side surface of the light-emitting functional layer and the portion of the surface of the light-emitting functional layer away from the base substrate;

the display substrate comprises a display region and a peripheral region around the display region,

the display substrate further comprises an auxiliary electrode in the peripheral region, the auxiliary electrode is in contact with a side surface of the first functional layer,

the display region comprises a plurality of pixels which are not separated by the peripheral region, an edge of the first functional layer in the peripheral region is closer to the auxiliary electrode than an edge of the second functional layer in the peripheral region, and a bottom surface of the auxiliary electrode, and the first and second function layer is coplanar.