Light emitting device with reflective sidewall

Patent metadata

Field	Value
Publication number	US-10886439-B2
Application number	US-202016786133-A
Country	US
Kind code	B2
Filing date	Feb 10, 2020
Priority date	May 9, 2017
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

Embodiments of the invention include a semiconductor light emitting device including a semiconductor structure. The semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A wavelength converting structure is disposed in a path of light emitted by the light emitting layer. A diffuse reflector is disposed along a sidewall of the semiconductor light emitting device and the wavelength converting structure. The diffuse reflector includes a pigment. A reflective layer is disposed between the diffuse reflector and the semiconductor structure. The reflective layer is a different material from the diffuse reflector.

First claim

What is being claimed is:

1. A device comprising:
a light emitting semiconductor structure;
a wavelength converting structure disposed on a top surface of the light emitting semiconductor structure;
a light blocking structure disposed along a sidewall of the light emitting semiconductor structure and the wavelength converting structure, the light blocking structure being a diffuse reflector; and
a reflective layer disposed between the light blocking structure and the semiconductor structure.

2. The device of claim 1 , wherein the reflective layer comprises alternating first and second insulating layers, the first insulating layers having a different index of refraction from the second insulating layers.

3. The device of claim 2 , wherein the diffuse reflector comprises reflective particles disposed in a transparent matrix.

4. The device of claim 1 , wherein the the reflective layer comprises a different material from the light blocking structure.

5. The device of claim 1 , wherein the light blocking structure comprises a pigment and the reflective layer comprises an oxide layer.

6. The device of claim 1 , wherein the light blocking structure is a same color as an off-state color of the wavelength converting structure and the reflective layer comprises an oxide layer.

7. The device of claim 1 , wherein the reflective layer comprises a nitride.

8. The device of claim 1 , wherein the reflective layer comprises a single layer.

9. The device of claim 1 , wherein the reflective layer comprises a metal layer.

10. The device of claim 9 , wherein the reflective layer comprises multiple layers including the metal layer and including at least one dielectric layer.

11. The device of claim 1 , wherein the reflective layer comprises multiple layers of insulating material.

12. The device of claim 1 , wherein the reflective layer comprises a porous material that is one of porous metal-oxide or porous glass.

13. The device of claim 1 , wherein the wavelength converting structure is wider in a direction parallel to the top surface than the light emitting semiconductor structure.

14. The device of claim 13 , wherein the reflective layer is not disposed between the wavelength converting structure and the light blocking structure.

15. The device of claim 1 , wherein the reflective layer is disposed between the wavelength converting structure and the light blocking structure.

16. The device of claim 1 , wherein a thickness of the reflective layer is from 1 micron to 50 microns.

17. The device of claim 1 , wherein a first light emitting device comprises the light emitting semiconductor structure, the wavelength converting structure, and the reflective layer, and a second light emitting device, and a second light emitting device disposed to be adjacent to the first light emitting device comprises a second light emitting semiconductor structure, a second wavelength converting structure, and a second reflective layer,
wherein the light blocking structure includes a portion disposed between the first light emitting device and the second light emitting device, and
wherein the wavelength converting structure of the first light emitting device has a different off-state color from the second wavelength converting structure of the second light emitting device.

18. The device of claim 17 , wherein the light blocking structure has a same color as an off-state color of the wavelength converting structure, and a different color as an off-state color of the second wavelength converting structure, and
wherein the second light emitting device includes a third wavelength converting structure disposed on the second wavelength converting structure that has a same color as an off-state color of the wavelength converting structure and as the light blocking structure.

19. A device comprising:
a light emitting semiconductor structure;
a wavelength converting structure disposed on a top surface of the light emitting semiconductor structure;
a light blocking structure disposed along a sidewall of the light emitting semiconductor structure and the wavelength converting structure and comprising a pigment the light blocking structure being a diffuse reflector; and
a reflective layer disposed between the light blocking structure and the semiconductor structure and comprising a different material from the light blocking structure.

20. A device comprising:
a light emitting semiconductor structure;
a wavelength converting structure disposed on a top surface of the light emitting semiconductor structure;
a light blocking structure disposed along a sidewall of the light emitting semiconductor structure and the wavelength converting structure and being a same color as an off-state color of the wavelength converting structure; and
a reflective layer disposed between the light blocking structure and the semiconductor structure and comprising a different material from the light blocking structure.

Assignees

• Lumileds Llc

Inventors

• Lu Dawei
• Shchekin Oleg

Classifications

• H10H20/8514

  characterised by their shape, e.g. plate or foil · CPC title

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title

• H10H20/814

  having reflecting means, e.g. semiconductor Bragg reflectors · CPC title

• H10H20/81

  Bodies · CPC title

• H10H20/856 Primary

  Reflecting means · CPC title