Method for manufacturing micro light-emitting diode array substrate

1. A method for manufacturing a micro light-emitting diode array substrate, comprising:

providing a drive substrate, the drive substrate comprising a plurality of sub-pixel regions, the plurality of sub-pixel regions being configured for bearing micro light-emitting diodes of different colors, and epitaxial layers of the micro light-emitting diodes of different colors having different thicknesses;

providing a base substrate, forming a plurality of micro light-emitting diodes on the base substrate, and transferring micro light-emitting diodes of same color on the base substrate as a whole onto the drive substrate; and

repeating the transferring the micro light-emitting diodes of same color on the base substrate as a whole onto the drive substrate in a sequence that the thicknesses of the epitaxial layers of the micro light-emitting diodes gradually increase, until each of the plurality of sub-pixel regions in pixel unit is provided with one of the micro light-emitting diodes having same color as the each sub-pixel region,

wherein after the transferring the micro light-emitting diodes of the same color on the base substrate as a whole onto the drive substrate, the method further comprises:

forming a distributed Bragg reflection dielectric film on a side of the micro light-emitting diodes away from the drive substrate.

2. The method according to claim 1 , wherein a blank region is formed between two micro light-emitting diodes, and the two micro light-emitting diodes correspond to two adjacent pixel units in a same row on the base substrate respectively.

3. The method according to claim 1 , wherein, among the micro light-emitting diodes and the plurality of the sub-pixel regions having same color as the micro light-emitting diodes, a total number of the plurality of the sub-pixel regions is an integral multiple of a total number of the micro light-emitting diodes on each base substrate.

4. The method according to claim 1 , wherein the drive substrate comprises an outermost layer electrode, and the outermost layer electrode and the micro light-emitting diode are bonded to each other.

5. The method according to claim 1 , wherein the micro light-emitting diodes of the different colors comprising a blue micro light-emitting diode, a green micro light-emitting diode, and a red micro light-emitting diode, and the thicknesses of epitaxial layers of the blue micro light-emitting diode, the green micro light-emitting diode and the red micro light-emitting diode gradually increase.

6. The method according to claim 1 , wherein the distributed Bragg reflection dielectric film is composed of a plurality of sub-layers arranged periodically and alternately, and the sub-layer comprises tantalum pentoxide and silicon oxide.

7. The method according to claim 6 , wherein a thickness of the sub-layer is λ/4n, where λ is a wavelength of a light-emitting center of a quantum well, and n is a refractive index of a material of the sub-layer.

8. The method according to claim 1 , wherein the micro light-emitting diode comprises a first electrode, an epitaxial layer, and a second electrode, and reflectivity of the distributed Bragg reflection dielectric film is less than reflectivity of the first electrode in the micro light-emitting diode.

9. The method according to claim 8 , wherein the forming the micro light-emitting diode comprises:

growing a semiconductor material layer on the base substrate;

forming a plurality of epitaxial layers arranged in an array by performing a patterning process on the semiconductor material layer; and

forming the first electrode and the second electrode on a side of the epitaxial layer away from the base substrate, an area of the first electrode being greater than an area of the second electrode.

10. The method according to claim 8 , wherein the forming the micro light-emitting diode comprises:

providing a transfer substrate, and growing a semiconductor material layer on the transfer substrate;

transferring the semiconductor material layer on the transfer substrate onto the base substrate, and removing the transfer substrate;

forming a plurality of epitaxial layers arranged in an array by performing a patterning process on the semiconductor material layer on the base substrate; and

forming the first electrode and the second electrode on a side of the epitaxial layer away from the base substrate, an area of the first electrode being greater than an area of the second electrode.

11. The method according to claim 1 , wherein the base substrate comprises a plurality of base substrates, each base substrate comprises a plurality of micro light-emitting diodes of same color, and the plurality of base substrates are different from one another in color of the micro light-emitting diodes.

12. The method according to claim 11 , after the transferring the micro light-emitting diodes of same color for each time, the method further comprises: stripping off the base substrate.

13. The method according to claim 12 , comprising:

providing a first base substrate having a plurality of micro light-emitting diodes of a first color formed thereon, and transferring the plurality of micro light-emitting diodes of the first color as a whole onto the drive substrate; and

stripping off the first base substrate.

14. The method according to claim 13 , wherein after the stripping off the first base substrate, the method further comprises:

providing a second base substrate having a plurality of micro light-emitting diodes of a second color formed thereon, and transferring the plurality of micro light-emitting diodes of the second color as a whole onto the drive substrate; and

stripping off the second base substrate.

15. The method according to claim 14 , wherein the base substrate is stripped off by wet etching, dry etching, or laser stripping.

16. The method according to claim 14 , wherein after the stripping off the second base substrate, the method further comprises:

providing a third base substrate having a plurality of micro light-emitting diodes of a third color formed thereon, and transferring the plurality of micro light-emitting diodes of the third color as a whole onto the drive substrate; and

stripping off the third base substrate.

17. The method according to claim 16 , wherein the first color comprises blue, the second color comprises green, and the third color comprises red.