Light emitting device and insulating anti-reflective layer used for light emitting device

Patent metadata

Field	Value
Publication number	US-2025107285-A1
Application number	US-202418796795-A
Country	US
Kind code	A1
Filing date	Aug 7, 2024
Priority date	Sep 25, 2023
Publication date	Mar 27, 2025
Grant date	—

Abstract

The present disclosure provides a face-up type ultraviolet light emitting device capable of improving the light extraction efficiency. The face-up type ultraviolet light emitting device includes an n-type layer made of n-type group III nitride semiconductor, an active layer formed on the n-type layer and made of group III nitride semiconductor, a p-type layer formed on the active layer 22 and made of p-type group III nitride semiconductor, a p-side electrode formed on one part on the p-type layer, an insulating anti-reflective layer formed on other part on the p-type layer, made of a material having insulating properties, and preventing reflection of ultraviolet light with an emission wavelength.

First claim

What is claimed is:

1 . A face-up type ultraviolet light emitting device comprising:
an n-type layer made of n-type group III nitride semiconductor; an active layer formed on the n-type layer and made of group III nitride semiconductor; a p-type layer formed on the active layer and made of p-type group III nitride semiconductor; a p-side electrode formed on one part on the p-type layer; and an insulating anti-reflective layer formed on other part on the p-type layer, made of a material having insulating properties, and preventing reflection of ultraviolet light with an emission wavelength.

2 . The light emitting device according to claim 1 , further comprising:
a p-side transparent electrode formed on and in contact with the p-type layer, and transmitting ultraviolet light with an emission wavelength, wherein the p-side electrode is formed on one part on the p-side transparent electrode, and the insulating anti-reflective layer is formed on other part on the p-side transparent electrode.

3 . The light emitting device according to claim 2 , wherein the refractive index of the insulating anti-reflective layer is set between the refractive index of the p-side transparent electrode and the refractive index of air.

4 . The light emitting device according to claim 1 , wherein the insulating anti-reflective layer has a multilayer structure formed by depositing materials having different refractive indices.

5 . The light emitting device according to claim 1 , wherein the insulating anti-reflective layer contains at least one selected from a group consisting of Hf oxide, Zr oxide, Si oxide, Al oxide, and Mg fluoride.

6 . The light emitting device according to claim 2 , wherein the p-side transparent electrode is formed thinner than the thickness of the insulating anti-reflective layer.

7 . The light emitting device according to claim 2 , wherein the thickness of the p-side transparent electrode is 20 nm or less.

8 . The light emitting device according to claim 7 , wherein the thickness of the insulating anti-reflective layer is 1 nm to 300 nm.

9 . The light emitting device according to claim 1 , wherein the p-type layer is made of GaN or AlGaN.

10 . An insulating anti-reflective layer used for a face-up type ultraviolet light emitting device, formed on a p-type layer, containing at least one selected from a group consisting of Hf oxide, Zr oxide, Si oxide, Al oxide, and Mg fluoride, and preventing reflectance of ultraviolet light with an emission wavelength.

Assignees

• Toyoda Gosei Kk

Inventors

• Makino Hiroaki
• Omoya Hideki
• Matsui Shinichi
• Mizutani Koichi

Classifications

• H10H20/84 Primary

  Coatings, e.g. passivation layers or antireflective coatings · CPC title

• H10H20/833

  Transparent materials · CPC title

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title

• H10H20/841 Primary

  Reflective coatings, e.g. dielectric Bragg reflectors · CPC title