Display substrate, manufacturing method thereof, and display device
A display substrate comprises a base substrate that comprises a first display area provided with multiple sub-pixels of different colors. At least one sub-pixel comprises a light-emitting element and a pixel driving circuit for driving the light-emitting element to emit light. The light-emitting element comprises a first electrode, a second electrode, and an organic light-emitting layer provided between the first electrode and the second electrode. The first electrode is a reflective electrode and is electrically connected to the pixel driving circuit. A first structure is provided on a side of the first electrode of the light-emitting element of a sub-pixel of at least one target color close to the base substrate, and a surface of the first structure close to the first electrode is uneven.
1 . A display substrate, comprising: a base substrate comprising a first display area provided with multiple sub-pixels of different colors; wherein
at least one sub-pixel of the multiple sub-pixels of different colors comprises a light-emitting element and a pixel driving circuit electrically connected to the light-emitting element;
the light-emitting element comprises a first electrode, a second electrode, and an organic light-emitting layer provided between the first electrode and the second electrode, the first electrode being electrically connected to the pixel driving circuit; and
a first structure is provided on a side of the first electrode of the light-emitting element of a sub-pixel of at least one target color close to the base substrate, a surface of the first structure close to the first electrode being uneven; wherein
wherein the first structure comprises at least one convex structure, the at least one convex structure is made of a metallic material, and the first structure further comprises a second insulating layer between the at least one convex structure and the first electrode.
2 . The display substrate according to claim 1 , wherein an orthographic projection of the first electrode on the base substrate comprises an orthographic projection of the at least one convex structure on the base substrate.
3 . The display substrate according to claim 2 , wherein the first structure further comprises a first insulating layer located on a side of the at least one convex structure close to the base substrate, and an orthographic projection of the first insulating layer on the base substrate comprises the orthographic projection of the first electrode on the base substrate.
4 . The display substrate according to claim 3 , wherein a surface of the first insulating layer close to the convex structure is flat.
5 . The display substrate according to claim 3 , wherein a surface of the first insulating layer close to the convex structure has a concave surface, and an orthographic projection of the convex structure on the base substrate does not overlap with an orthographic projection of the concave surface of the first insulating layer on the base substrate.
6 . The display substrate according to claim 1 , wherein
the first structure has a flat portion and at least one non-flat portion; an orthographic projection of the flat portion on the base substrate does not overlap with an orthographic projection of the at least one non-flat portion on the base substrate; and
an orthographic projection of the first electrode on the base substrate comprises an orthographic projection of the at least one non-flat portion on the base substrate.
7 . The display substrate according to claim 6 , wherein the at least one non-flat portion comprises at least one of a convex structure and a concave structure; and a thickness of the first structure at the convex structure is greater than a thickness at the flat portion, and a thickness of the first structure at the concave structure is less than a thickness at the flat portion.
8 . The display substrate according to claim 2 , wherein in a plane perpendicular to the base substrate, the convex structure comprises a top surface and a slope connecting to the top surface, and an angle between a tangent of the slope surface and a plane parallel to the base substrate is about 3° to 30°.
9 . The display substrate according to claim 2 , wherein the convex structure has a height of about 100 nm to 5 μm.
10 . The display substrate according to claim 2 , wherein
in a plane parallel to the base substrate, a length of the convex structure in a first direction is less than a length of the corresponding sub-pixel in the first direction, and a length of the convex structure in a second direction is less than a length of the corresponding sub-pixel in the second direction; and
the first direction crosses the second direction.
11 . The display substrate according to claim 2 , wherein in a plane parallel to the base substrate, the convex structure has a width of about 500 nm to 15 μm, and a non-planar structure formed by the first electrode based on the convex structure has a width of about 1 μm to 25 μm.
12 . The display substrate according to claim 1 , wherein a shape of the non-planar structure formed by the first electrode based on the first structure is different from a shape of the base substrate; and/or
the first electrode is a reflective electrode; and/or
the sub-pixel of the at least one target color comprises at least one of a blue sub-pixel, a green sub-pixel, and a red sub-pixel.
13 . The display substrate according to claim 6 , wherein the pixel driving circuit comprises an active layer, a first gate metal layer, a second gate metal layer, a first source-drain metal layer, and a second source-drain metal layer that are sequentially provided on the base substrate, the first structure is provided between the second source-drain metal layer and the light-emitting element, and a thickness of the first structure is less than or equal to 2 μm;
the first source-drain metal layer and the second source-drain metal layer satisfy at least one of the following:
an overlapping area of orthographic projections of the first source-drain metal layer and the second source-drain metal layer of a pixel driving circuit of a sub-pixel of the at least one target color on the base substrate is greater than an overlapping area of orthographic projections of the first source-drain metal layer and the second source-drain metal layer of a pixel driving circuit of a sub-pixel of a color other than the at least one target color on the base substrate; and
a thickness of the second source-drain metal layer of the pixel driving circuit of the sub-pixel of the at least one target color is greater than a thickness of the second source-drain metal layer of the pixel driving circuit of the sub-pixel of the color other than the at least one target color.
14 . The display substrate according to claim 1 , wherein the base substrate further comprises a second display area; and the second display area is a flat surface display area, and the first display area is a curved display area or a bent display area around the second display area.
15 . The display substrate according to claim 14 , wherein second electrodes of the first display area and the second display area are integrated, and insulating layers of the first display area and the second display area are integrated.
16 . A display device, comprising the display substrate according to claim 1 .
17 . A manufacturing method of a display substrate, comprising:
forming multiple sub-pixels of different colors in a first display area of a base substrate; wherein at least one sub-pixel of the multiple sub-pixels of different colors comprises a light-emitting element and a pixel driving circuit electrically connected to the light-emitting element; and the light-emitting element comprises a first electrode, a second electrode and an organic light-emitting layer provided between the first electrode and the second electrode, the first electrode being electrically connected to the pixel driving circuit; and
forming a first structure on a side of the first electrode of the light-emitting element of a sub-pixel of at least one target color close to the base substrate, a surface of the first structure close to the first electrode being uneven; wherein
wherein the first structure comprises at least one convex structure, the at least one convex structure is made of a metallic material, and the first structure further comprises a second insulating layer between the at least one convex structure and the first electrode.
18 . The manufacturing method according to claim 17 , wherein the step of forming the multiple sub-pixels of different colors in the first display area of the base substrate comprises:
forming multiple pixel driving units on the base substrate; and
forming a first structure on a side of the first electrode of the light-emitting element of a sub-pixel of at least one target color close to the base substrate, a surface of the first structure close to the first electrode being uneven;
wherein an orthographic projection of the first electrode on the base substrate comprises an orthographic projection of the at least one convex structure on the base substrate.
19 . The manufacturing method according to claim 18 , wherein the step of forming the first structure on the side of the first electrode of the light-emitting element of the sub-pixel of at least one target color close to the base substrate comprises at least one of the following steps:
etching a metal film by wet etching process to form a convex structure of the first structure; and
using a photosensitive organic material for exposure and development to form a convex structure of the first structure.