LED STRUCTURE AND PREPARING METHOD OF LED STRUCTURE

Abstract

Disclosed are an LED structure and a preparing method of an LED structure. The LED structure includes: an LED light emitting unit including a first semiconductor layer, a light emitting layer and a second semiconductor layer which are stacked; and a first stress layer surrounding the LED light emitting unit and covering a side wall of the LED light emitting unit. In the present disclosure, the first stress layer is configured to apply a stress to the side wall of the LED light emitting unit, adjust a wavelength of the LED structure, and improve a wavelength uniformity of the LED structure. In addition, since a side wall of the LED structure is extruded, and a luminous efficiency of the LED structure is effectively improved.

Description

Claims

1. A Light Emitting Diode (LED) structure, comprising: a substrate structure;at least one LED light emitting unit located on the substrate structure, the LED light emitting unit comprising a first semiconductor layer, a light emitting layer and a second semiconductor layer which are stacked; anda first stress layer surrounding the LED light emitting unit and covering a side wall of the LED light emitting unit, wherein the first stress layer is configured to apply a compressive stress to the side wall of the LED light emitting unit in a direction perpendicular to the side wall of the LED light emitting unit, and apply a tensile stress to the side wall of the LED light emitting unit in a direction parallel to the side wall of the LED light emitting unit.

2. The LED structure according to claim 1, wherein the first stress layer is insulated from the LED light emitting unit.

3. The LED structure according to claim 1, wherein a material of the first stress layer comprises one or more of SiN, SiO2 and diamond-like materials.

4. The LED structure according to claim 1, wherein the first stress layer has a trench, and the trench at least partially penetrates the first stress layer.

5. The LED structure according to claim 1, wherein a thicknesses of the first stress layer at side walls of LED light emitting units located at different positions are different.

6. The LED structure according to claim 1, wherein a material of the first stress layer is SiN or SiO2, and Si components in the first stress layer at side walls of LED light emitting units located at different positions are different.

7. The LED structure according to claim 4, wherein the trench completely penetrates the first stress layer, a second stress layer is disposed in the trench, and the second stress layer is configured to apply a compressive stress to the side wall of the LED light emitting unit in a direction perpendicular to the side wall of the LED light emitting unit, and apply a tensile stress to the side wall of the LED light emitting unit in a direction parallel to the side wall of the LED light emitting unit.

8. The LED structure according to claim 7, wherein a material of the second stress layer is a III-V group compound, and a lattice constant of the material of the second stress layer is greater than a lattice constant of a material in the LED light emitting unit.

9. The LED structure according to claim 8, wherein the material of the second stress layer is InGaN.

10. The LED structure according to claim 1, wherein the LED structure further comprises: a first electrode electrically connected to the first semiconductor layer; and a second electrode electrically connected to the second semiconductor layer.

11. The LED structure according to claim 7, wherein a material of the second stress layer is a piezoelectric material; and the LED structure further comprises:a third electrode, wherein the second stress layer is electrically connected to the third electrode.

12. A preparing method of an LED structure, comprising: forming an LED light emitting unit on a substrate structure, the LED light emitting unit comprising a first semiconductor layer, a light emitting layer and a second semiconductor layer which are stacked; andforming a first stress layer surrounding the LED light emitting unit, wherein the first stress layer covers a side wall of the LED light emitting unit, and is configured to apply a compressive stress to the side wall of the LED light emitting unit in a direction perpendicular to the side wall of the LED light emitting unit, and apply a tensile stress to the side wall of the LED light emitting unit in a direction parallel to the side wall of the LED light emitting unit.

13. The preparing method of an LED structure according to claim 12, wherein a material of the first stress layer comprises one or more of SiN, SiO2 and diamond-like materials.

14. The preparing method of an LED structure according to claim 12, wherein the forming a first stress layer surrounding the LED light emitting unit comprises: controlling components of the first stress layer located at different positions to be different, and/or, controlling formation temperatures of the first stress layer located at different positions to be different.

15. The preparing method of an LED structure according to claim 12, wherein the forming a first stress layer surrounding the LED light emitting unit comprises: controlling, by local etching or local increase of thickness, a thicknesses of the first stress layer located at different positions to be different.

16. The preparing method of an LED structure according to claim 12, further comprising: forming a trench in the first stress layer, the trench penetrating the first stress layer, and forming a second stress layer in the trench.

17. The preparing method of an LED structure according to claim 16, wherein a material of the second stress layer is a III-V group compound, and a lattice constant of the material of the second stress layer is greater than a lattice constant of a material in the LED light emitting unit.

18. The preparing method of an LED structure according to claim 17, wherein the material of the second stress layer is InGaN.

19. The preparing method of an LED structure according to claim 12, wherein the preparing method of an LED structure further comprises: preparing a first electrode and a second electrode, wherein the first electrode is electrically connected to the first semiconductor layer, and the second electrode is electrically connected to the second semiconductor layer.

20. The preparing method of an LED structure according to claim 16, wherein a material of the second stress layer is a piezoelectric material, and after forming the second stress layer in the trench, the preparing method of an LED structure further comprises: preparing a third electrode, wherein the third electrode is electrically connected to the second stress layer.