EPITAXIAL WAFER, METHOD FOR PREPARING THE SAME AND DISPLAY DEVICE

1 . An epitaxial wafer, comprising an N-type doped layer, a functional well structure and a P-type doped structure sequentially arranged in a stacked manner;

wherein the functional well structure comprises a light emitting substructure, and the light emitting substructure comprises a redundant barrier layer, wherein the redundant barrier layer is disposed between the N-type doped layer and the P-type doped structure.

2 . The epitaxial wafer according to claim 1 , wherein the light emitting substructure further comprises a multi-period light emitting layer disposed between the N-type doped layer and the redundant barrier layer.

3 . The epitaxial wafer according to claim 2 , wherein the multi-period light emitting layer comprises a plurality of light emitting stack layers, wherein each of the plurality of light emitting stack layers comprises a first barrier layer and a first well layer, and the first barrier layer is disposed between the first well layer of a same light emitting stack layer and the N-type doped layer.

4 . The epitaxial wafer according to claim 1 , wherein the P-type doped structure comprises a P-type layer and a multi-period doped layer disposed between the P-type layer and the functional well structure.

5 . The epitaxial wafer according to claim 4 , wherein the multi-period doped layer comprises a plurality of doped stack layers, and each of the plurality of doped stack layers comprises a ternary doped layer and a binary doped layer, wherein the ternary doped layer is disposed between the binary doped layer of a same doped stack layer and the functional well structure.

6 . The epitaxial wafer according to claim 1 , wherein the functional well structure further comprises a stress adjustment structure disposed between the N-type doped layer and the light emitting substructure.

7 . The epitaxial wafer according to claim 6 , wherein the stress adjustment structure comprises a plurality of stress adjustment stack layers, and each of the plurality of stress adjustment stack layers comprises a third well layer and a third barrier layer, wherein the third barrier layer is disposed between the third well layer of a same adjustment stack layer and the N-type doped layer.

8 . The epitaxial wafer according to claim 1 , further comprising an undoped layer, a buffer layer and a substrate;

wherein the substrate is disposed on a side of the N-type doped layer away from the P-type doped structure;

the buffer layer is disposed between the substrate and the N-type doped layer; and

the undoped layer is disposed between the buffer layer and the N-type doped layer.

9 . The epitaxial wafer according to claim 1 , wherein the functional well structure further comprises a transition substructure disposed between the light emitting substructure and the N-type doped layer.

10 . The epitaxial wafer according to claim 9 , wherein the transition substructure comprises a plurality of transition stack layers, and each of the plurality of transition stack layers comprises a second barrier layer and a second well layer, wherein the second barrier layer is disposed between the second well layer of a same transition stack layer and the N-type doped layer.

11 . A display device, comprising an epitaxial wafer according to claim 1 .

12 . A method for preparing an epitaxial wafer according to claim 1 , comprising:

forming the N-type doped layer on a substrate;

forming the functional well structure on the N-type doped layer, wherein the step of forming the functional well structure on the N-type doped layer comprises: forming the redundant barrier layer on the N-type doped layer; and

forming the P-type doped structure on the redundant barrier layer.

13 . The method according to claim 12 , wherein the step of forming the functional well structure on the N-type doped layer further comprises: forming a multi-period light emitting layer on a side of the N-type doped layer away from the substrate before the step of forming the redundant barrier layer.

14 . The method according to claim 13 , wherein the step of forming the functional well structure further comprises: forming a stress adjustment structure on the side of the N-type doped layer away from the substrate before forming the multi-period light emitting layer.

15 . The method according to claim 12 , wherein the step of forming the P-type doped structure comprises: forming a multi-period doped layer on a side of the redundant barrier layer away from the N-type doped layer, and forming a P-type layer on a side of the multi-period doped layer away from the N-type doped layer.

16 . The method according to claim 15 , wherein the step of forming the multi-period doped layer comprises: forming a doped stack layer, and the step of forming the doped stack layer comprises: forming a ternary doped layer, and forming a binary doped layer on a side of the ternary doped layer away from the substrate; and

wherein the step of forming the multi-period doped layer comprises performing the step of forming the doped stack layer for a plurality of times to form a plurality of doped stack layers in a direction of a line connecting the N-type doped layer and the P-type doped structure.

17 . The method according to claim 12 , further comprising: forming a buffer layer and an undoped layer sequentially on the substrate before the step of forming the N-type doped layer.

18 . The method according to claim 12 , further comprising: performing annealing after the step of forming the P-type doped structure.

19 . The method according to claim 12 , wherein the step of forming the functional well structure on the N-type doped layer further comprises sequentially forming a transition substructure and a light emitting substructure on the N-type doped layer, wherein the light emitting substructure comprises the redundant barrier layer.

20 . The method according to claim 19 , wherein the step of forming the transition substructure comprises: forming a transition stack layer on the N-type doped layer, and the step of forming the transition stack layer on the N-type doped layer comprises: forming a second barrier layer, and forming a second well layer on a side of the second barrier layer away from the N-type doped layer; and

wherein the step of forming the transition substructure comprises performing the step of forming the transition stack layer on the N-type doped layer for a plurality of times to form a plurality of transition stack layers in a direction of a line connecting the N-type doped layer and the P-type doped structure.