Light emitting device with reflective sidewall

Patent metadata

Field	Value
Publication number	US-10224358-B2
Application number	US-201715590802-A
Country	US
Kind code	B2
Filing date	May 9, 2017
Priority date	May 9, 2017
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

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 semiconductor light emitting device comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a wavelength converting structure disposed over the light emitting layer;
a light blocking structure disposed along a sidewall of the semiconductor light emitting device and the wavelength converting structure, the light blocking structure comprising a pigment; and
a reflective layer disposed between the light blocking structure and the semiconductor structure, the reflective layer including alternating first and second insulating layers, the first insulating layers having a different index of refraction from the second insulating layers.

2. The device of claim 1 wherein the light blocking structure comprises particles disposed in a transparent material.

3. The device of claim 1 wherein a first surface of the light blocking structure is at the same elevation as a first surface of the wavelength converting structure.

4. The device of claim 1 wherein the reflective layer comprises an oxide and the light blocking structure comprises silicone.

5. A device comprising:
a semiconductor light emitting device comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a wavelength converting structure disposed over the light emitting layer;
a light blocking structure disposed along a sidewall of the semiconductor light emitting device and the wavelength converting structure, the light blocking structure comprising a pigment, and the light blocking structure being the 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, the reflective layer including a different material from the light blocking structure.

6. The device of claim 1 wherein the light blocking structure is non-white.

7. A device comprising:
a semiconductor light emitting diode comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a wavelength converting structure disposed over the light emitting layer;
a diffuse reflector disposed along a sidewall of the semiconductor light emitting device and the wavelength converting structure, the diffuse reflector comprising particles disposed in a transparent material; and
a reflective layer disposed between the diffuse reflector and the semiconductor structure, wherein the reflective layer comprises an oxide layer.

8. The device of claim 7 wherein the particles are TiO 2 and the transparent material is silicone.

9. The device of claim 7 wherein the reflective layer comprises alternating first and second insulating layers, wherein the first insulating layers have a different index of refraction from the second insulating layers.

10. A device comprising:
a semiconductor light emitting diode comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a wavelength converting structure disposed over the light emitting layer;
a diffuse reflector disposed along a sidewall of the semiconductor light emitting device and the wavelength converting structure, the diffuse reflector comprising particles disposed in a transparent material, the diffuse reflector having the same color as an off-state color of the wavelength converting structure; and
a reflective layer disposed between the diffuse reflector and the semiconductor structure, wherein the reflective layer comprises an oxide layer.

11. The device of claim 7 wherein the diffuse reflector is non-white.

12. A device comprising:
a first semiconductor light emitting diode comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a first wavelength converting structure disposed over the first light emitting diode;
a second semiconductor light emitting diode comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
a second wavelength converting structure disposed over the second light emitting diode;
a third wavelength converting structure, wherein the second wavelength converting structure is disposed between the third wavelength converting structure and the second semiconductor light emitting diode;
a thin reflective layer disposed between the second and third wavelength converting structures; and
a light blocking layer disposed between the first and second wavelength converting structures; wherein:
an off-state appearance of the first and third wavelength converting structures and the light blocking layer is the same color; and
an off-state appearance of the second wavelength converting structure is a different color from the off-state appearance of the first and third wavelength converting structures.

13. The device of claim 12 wherein the thin reflective layer is a first thin reflective layer, the device further comprising:
a second thin reflective layer disposed between the first semiconductor light emitting diode and the light blocking structure; and
a third thin reflective layer disposed between the second semiconductor light emitting diode and the light blocking structure.

Assignees

• Lumileds Llc

Inventors

• Lu Dawei
• Shchekin Oleg

Classifications

• H05B33/22

  characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21V7/04

  Optical design · CPC title

• F21V7/0025

  Combination of two or more reflectors for a single light source (array of reflectors for a cluster of light sources F21V7/0083) · CPC title

• F21V7/22

  characterised by materials, surface treatments or coatings, e.g. dichroic reflectors · CPC title