Display substrate comprising a light-reflecting wall having a light-transmissive wall and a light-reflecting layer covering a top surface and side surfaces of the light-transmissive wall, method for manufacturing the same, and display device

1. A display substrate, comprising:

a base substrate;

a black matrix pattern on the base substrate;

a plurality of display units respectively in a plurality of regions defined by the black matrix pattern; and

a light-reflecting wall between at least two adjacent display units, wherein at least one display unit of the at least two adjacent display units is a quantum dot display unit,

wherein the light-reflecting wall comprises:

a light-transmissive wall; and

a light-reflecting layer covering a top surface and side surfaces of the light-transmissive wall, wherein a reflectance of the light-reflecting layer to the light in the first wavelength range is greater than the preset threshold;

wherein the light-reflecting layer comprises a plurality of first refractive films and a plurality of second refractive films, the first refractive films and the second refractive films are arranged alternately in a stacked manner, a refractive index of the first refractive films and a refractive index of the second refractive films are different, and the first refractive films are made of TiO2 and the second refractive films are made of SiO2;

wherein the light-reflecting layer comprises:

4 first refractive films and 3 second refractive films; or

5 first refractive films and 4 second refractive films; or

6 first refractive films and 5 second refractive films; or

7 first refractive films and 6 second refractive films; and

wherein a thickness of the first refractive films and a thickness of the second refractive films are set such that a reflectance of the light-reflecting layer to light in a first wavelength range is greater than a preset threshold of 80%.

2. The display substrate according to claim 1 , wherein:

a first one of the at least two adjacent display units is a quantum dot display unit, and a second one of the at least two adjacent display units is a light-transmissive unit; or

the at least two adjacent display units are all quantum dot display units.

3. The display substrate according to claim 1 , wherein the light-reflecting wall is provided between every two adjacent display units of the plurality of display units.

4. The display substrate according to claim 3 , wherein:

the reflectance of the light-reflecting wall to blue light is greater than the preset threshold, and the plurality of display units comprises a red light quantum dot display unit for emitting red light, a green light quantum dot display unit for emitting green light, and a light-transmissive unit for transmitting blue light; or

the reflectance of the light-reflecting wall to green light is greater than the preset threshold, and the plurality of display units comprises a red light quantum dot display unit for emitting red light, a blue light quantum dot display unit for emitting blue light, and a light-transmissive unit for transmitting green light; or

the reflectance of the light-reflecting wall to red light is greater than the preset threshold, the plurality of display units comprises a green light quantum dot display unit for emitting green light, a blue light quantum dot display unit for emitting blue light, and a light-transmissive unit for transmitting red light.

5. The display substrate according to claim 1 , wherein the light-reflecting wall is at a side of the black matrix pattern away from the base substrate.

6. The display substrate according to claim 1 , wherein the black matrix pattern comprises a plurality of light-shielding units, and an area of an orthographic projection of the light-reflecting wall onto the base substrate is less than or equal to an area of an orthographic projection of the light-shielding unit onto the base substrate.

7. The display substrate according to claim 1 , wherein the black matrix pattern comprises a plurality of light-shielding units, and an area of an orthographic projection of the light-reflecting wall onto the base substrate is greater than an area of an orthographic projection of the light-shielding unit onto the base substrate.

8. The display substrate according to claim 1 , wherein a material of the light-transmissive wall is resin.

9. The display substrate according to claim 1 , wherein a distance between a top surface of the light-reflecting wall and the base substrate is not less than a distance between a top surface of the display unit and the base substrate, the top surface of the light-reflecting wall is a surface of the light-reflecting wall away from the base substrate, and the top surface of the display unit is a surface of the display unit away from the base substrate.

10. A method for manufacturing a display substrate, comprising:

forming a black matrix pattern and a plurality of display units on a base substrate, wherein the plurality of display units is respectively in a plurality of regions defined by the black matrix pattern; and

forming a light-reflecting wall between at least two adjacent display units, wherein at least one display unit of the at least two adjacent display units is a quantum dot display unit, and a reflectance of the light-reflecting wall to light in a first wavelength range is greater than a preset threshold;

wherein forming the light-reflecting wall between the at least two adjacent display units comprises:

forming a light-transmissive wall at a side of the black matrix pattern away from the base substrate; and

forming a light-reflecting layer covering a top surface and side surfaces of the light-transmissive wall at the side of the black matrix pattern away from the base substrate;

wherein forming the light-reflecting layer comprises:

forming a plurality of first refractive films and a plurality of second refractive films, wherein the first refractive films and the second refractive films are arranged alternately in a stacked manner, and a refractive index of the first refractive films and a refractive index of the second refractive films are different, and the first refractive films are made of TiO2 and the second refractive films are made of SiO2;

wherein the light-reflecting layer comprises:

4 first refractive films and 3 second refractive films; or

5 first refractive films and 4 second refractive films; or

6 first refractive films and 5 second refractive films; or

7 first refractive films and 6 second refractive films; and

wherein a thickness of the first refractive films and a thickness of the second refractive films are set such that a reflectance of the light-reflecting layer to light in a first wavelength range is greater than a preset threshold of 80%.

11. A display device, comprising a display substrate, wherein the display substrate comprises:

a base substrate;

a black matrix pattern on the base substrate;

a plurality of display units respectively in a plurality of regions defined by the black matrix pattern; and

a light-reflecting wall between at least two adjacent display units, wherein at least one display unit of the at least two adjacent display units is a quantum dot display unit;

wherein the light-reflecting wall comprises:

a light-transmissive wall; and

a light-reflecting layer covering a top surface and side surfaces of the light-transmissive wall, wherein a reflectance of the light-reflecting layer to the light in the first wavelength range is greater than the preset threshold;

wherein the light-reflecting layer comprises a plurality of first refractive films and a plurality of second refractive films, the first refractive films and the second refractive films are arranged alternately in a stacked manner, a refractive index of the first refractive films and a refractive index of the second refractive films are different, and the first refractive films are made of TiO2 and the second refractive films are made of SiO2;

wherein the light-reflecting layer comprises:

4 first refractive films and 3 second refractive films; or

5 first refractive films and 4 second refractive films; or

6 first refractive films and 5 second refractive films; or

7 first refractive films and 6 second refractive films; and

wherein a thickness for first refractive films and a thickness for second refractive films are set such that a reflectance of the light-reflecting layer to light in a first wavelength range is greater than a preset threshold of 80%.

12. The display device according to claim 11 , further comprising:

an array substrate opposite to the display substrate;

a liquid crystal layer between the display substrate and the array substrate;

a backlight module at a side of the array substrate away from the display substrate;

wherein the liquid crystal layer is at a light-emitting side of the backlight module, the light in the first wavelength range is blue light, and the backlight module is a blue light backlight module.

13. The display device according to claim 12 , further comprising:

a first polarizer between the array substrate and the backlight module; and

a second polarizer between the liquid crystal layer and the display substrate, wherein a direction of a light transmission axis of the second polarizer is perpendicular to a direction of a light transmission axis of the first polarizer.

14. The display device according to claim 13 , wherein the second polarizer is a wire grip polarizer having a period in a range of 80 to 140 nm, a duty ratio in a range of 0.4 to 0.6 and a depth-to-width ratio in a range of 2:1 to 3:1.