Display substrate and manufacturing method thereof and display panel

1. A display substrate, comprising a display area and a reflective layer, wherein

at least a portion of the reflective layer is in the display area; and

the reflective layer comprises a metasurface facing a display side of the display substrate, and the metasurface comprises a plurality of convex structures which have metamaterial properties and are scattered;

the reflective layer further comprises a base layer, and the base layer comprises a plurality of grooves facing the display side of the display substrate;

the plurality of convex structures are in one-to-one correspondence with the grooves, and each of the plurality of convex structures is overlapped with the corresponding groove in a direction perpendicular to a plane that the reflective layer is located and protrudes from a surface of the base layer.

2. The display substrate according to claim 1 , wherein the plurality of convex structures are in an array.

3. The display substrate according to claim 1 , further comprising a plurality of sub-pixels arranged in an array in the display area,

wherein each of the sub-pixels comprises a pixel electrode;

the pixel electrode is facing the metasurface of the reflective layer, or on a side of the reflective layer away from the metasurface.

4. The display substrate according to claim 1 , wherein the base layer is made of a porous material.

5. The display substrate according to claim 4 , wherein

the base layer is a porous alumina layer or a porous titanium oxide layer.

6. A display panel, comprising the display substrate according to claim 1 .

7. The display panel according to claim 6 , further comprising an opposed substrate and a liquid crystal layer, wherein

the opposed substrate and the display substrate are arranged oppositely to form a cell, and the liquid crystal layer is between the opposed substrate and the display substrate.

8. A method of manufacturing a display substrate, the display substrate comprising a display area, the method comprising:

forming a reflective layer at least in the display area,

wherein the reflective layer comprises a metasurface facing a display side of the display substrate, and the metasurface comprises a plurality of convex structures which have metamaterial properties and are scattered; and

wherein forming the reflective layer comprises forming a base layer, wherein the base layer comprises a plurality of grooves, the plurality of convex structures are in one-to-one correspondence with the grooves, and each of the plurality of convex structures is overlapped with the corresponding groove in a direction perpendicular to a plane that the reflective layer is located and protrudes from a surface of the base layer.

9. The manufacturing method according to claim 8 , wherein forming the reflective layer further comprises:

applying nanospheres on the base layer, to allow the nanospheres to be in the grooves,

wherein portions of the nanospheres protruding from the groove form the plurality of convex structures.

10. The manufacturing method according to claim 9 , wherein

at least one of the nanospheres has a diameter ranging from 100 to 200 nanometers, a diameter of each of the grooves ranges from 150 to 250 nm, and a minimum spacing between adjacent grooves ranges from 100 to 200 nm.

11. The manufacturing method according to claim 9 , wherein forming the base layer and applying the nanospheres on the base layer comprises:

depositing a metal material to form a metal thin film and oxidizing a surface portion of the metal thin film to form a first metal oxide layer with plural pores, wherein an unoxidized portion of the metal thin film is formed as the base layer;

removing the first metal oxide layer, wherein a plurality of grooves corresponding to the plural pores are formed in a surface of the base layer; and

applying a suspended solution containing nanospheres on the surface of the base layer and evaporating the suspended solution, to embed the nanospheres in the grooves.

12. The manufacturing method according to claim 11 , wherein the forming a base layer with grooves and applying nanospheres further comprises:

oxidizing the surface of the base layer before the suspended solution is applied, to increase a depth of the grooves; and/or

etching the surface of the base layer with an etching solution to increase a diameter of the grooves.

13. The manufacturing method according to claim 12 , wherein the metal material is aluminum; the oxidizing the surface of the base layer and/or oxidizing the surface of the base layer comprises:

performing oxidation by taking the metal thin film and/or the base layer as an anode, wherein an oxidation voltage of the anode is 30-50V, a electrolyte is an oxalic acid electrolyte with a concentration of 0.3 mol/L, and a temperature is 5-10° C.