Display substrate, manufacturing method therefor, and display apparatus

1 . A display substrate comprising multiple top-emission quantum dot light-emitting devices, and each of the multiple top-emission quantum dot light-emitting devices comprising:

a first electrode and a second electrode arranged opposite to each other;

a quantum dot light-emitting layer between the first electrode and the second electrode; and

an electron transport layer between the first electrode and the quantum dot light-emitting layer;

wherein, a metal reflection layer is provided inside the electron transport layer;

wherein the multiple top-emission quantum dot light-emitting devices comprise multiple top-emission quantum dot light-emitting devices with different emission wavelengths; and

a distance between the metal reflection layer and the first electrode in each of the multiple top-emission quantum dot light-emitting devices is inversely correlated with an emission wavelength of the each of the multiple top-emission quantum dot light-emitting devices;

wherein a proportion of oxygen vacancies on a surface of the electron transport layer in contact with the first electrode is less than a proportion of oxygen vacancies on a surface of the electron transport layer in contact with the metal reflection layer; and

wherein a ratio of an area of the metal reflection layer to an area of the electron transport layer in each of the multiple top-emission quantum dot light-emitting devices ranges from 50% to 100%.

2 . The display substrate according to claim 1 , wherein an included angle between a plane where the metal reflection layer is located and a plane where the electron transport layer is located is less than 1‰ degree.

3 . The display substrate according to claim 1 , wherein the multiple top-emission quantum dot light-emitting devices with different emission wavelengths comprise red top-emission quantum dot light-emitting devices, green top-emission quantum dot light-emitting devices, and blue top-emission quantum dot light-emitting devices; and

a distance between a metal reflection layer and a first electrode in the red top-emission quantum dot light-emitting devices is a first distance, a distance between a metal reflection layer and a first electrode in the green top-emission quantum dot light-emitting devices is a second distance, and a distance between a metal reflection layer and a first electrode in the blue top-emission quantum dot light-emitting devices is a third distance; wherein the first distance ranges from 0 to 20 nm, the second distance ranges from 20 nm to 40 nm, and the third distance ranges from 40 nm to 60 nm.

4 . The display substrate according to claim 1 , wherein the metal reflection layer has a planar structure; and

wherein the area of the metal reflection layer is smaller than the area of the electron transport layer; and

the metal reflection layer is located in a central region of the electron transport layer.

5 . The display substrate according to claim 1 , wherein the metal reflection layer comprises multiple hollow structures arranged separately; and

wherein the multiple hollow structures are arranged in an array.

6 . The display substrate according to claim 5 , further comprising multiple data lines extending along a first direction and arranged along a second direction;

wherein the multiple hollow structures are strip-shaped hollow structures extending along the second direction and arranged along the first direction; and

the first direction and the second direction intersect.

7 . The display substrate according to claim 5 , wherein a distance between adjacent hollow structures in each of the multiple top-emission quantum dot light-emitting devices is positively correlated with an emission wavelength of the each of the multiple top-emission quantum dot light-emitting devices.

8 . The display substrate according to claim 1 , wherein the metal reflection layer comprises multiple reflective parts arranged separately and a hollow structure between adjacent reflective parts;

wherein the multiple reflective parts are arranged in an array.

9 . The display substrate according to claim 8 , further comprising multiple data lines extending along a first direction and arranged along a second direction;

wherein the multiple reflective parts are strip-shaped reflective parts extending along the second direction and arranged along the first direction; and

the first direction and the second direction intersect.

10 . The display substrate according to claim 8 , wherein a distance between adjacent reflective parts in each of the multiple top-emission quantum dot light-emitting devices is positively correlated with an emission wavelength of the each of the multiple top-emission quantum dot light-emitting devices.

11 . The display substrate according to claim 1 , wherein a reflectance of the metal reflection layer in a visible light range ranges from 30% to 60%; and

wherein a work function of the metal reflection layer ranges from 2.2 eV to 4.2 eV, and a thickness of the metal reflection layer ranges from 3 nm to 5 nm.

12 . The display substrate according to claim 1 , wherein a material of the metal reflection layer comprises Mg, Ag, or Al; and

wherein a material of the electron transport layer comprises metal oxide nanoparticles, and a surface of the metal reflection layer facing away from the first electrode is uneven.

13 . The display substrate according to claim 1 , wherein a thickness of the electron transport layer ranges from 50 nm to 80 nm.

14 . The display substrate according to claim 1 , further comprising:

a hole transport layer between the quantum dot light-emitting layer and the second electrode; and

a hole injection layer between the hole transport layer and the second electrode;

wherein a thickness of the hole transport layer ranges from 10 nm to 40 nm, a thickness of the hole injection layer ranges from 3 nm to 7 nm, and a thickness of the quantum dot light-emitting layer ranges from 10 nm to 40 nm.

15 . A display apparatus comprising the display substrate according to claim 1 .