Enraytek Optoelectronics Co., Ltd.

Houyong Ma

Qiming Li

Yu Zhang

Huiwen Xu

Jing Ju

Zhengzhang You

Jingchao Xie

A method for recycling a sapphire substrate is disclosed. The method includes the steps of: high-temperature baking, wherein an intact epitaxial wafer to be scrapped is placed and baked in a baking oven at a high temperature of from 600&#xb0; C. to 1000&#xb0; C., and wherein the epitaxial wafer contains the sapphire substrate; and high-temperature rinsing in a concentrated acid, wherein the baked epitaxial wafer is then rinsed in the concentrated acid having a concentration ranging from 60% to 99% at a high temperature of from 160&#xb0; C. to 300&#xb0; C. The method can be used for recycling both patterned and smooth sapphire substrates.

Sapphire substrate recycling method

A GaN-based LED epitaxial structure comprises a non-doped GaN buffer layer, an undoped GaN layer, an N-type GaN layer, an InGaN/GaN superlattice quantum well structure, a multiple quantum well luminous layer structure, an AlGaN layer, a low-temperature P-type layer, a P-type electron blocking layer and a P-type GaN layer which are sequentially stacked, wherein the non-doped GaN buffer layer comprises a sandwich structure consisting of a GaN layer, an AlGaN layer and a GaN layer which are sequentially stacked. For the GaN-based LED epitaxial structure and the preparation method thereof, the non-doped GaN buffer layer with the sandwich structure consisting of the GaN layer, the AlGaN layer and the GaN layer is used as a buffer layer, the buffer layer changes light scattering directions by using materials with different refractive indexes and thus the luminous efficiency can be improved.

GaN-based LED epitaxial structure and preparation method thereof

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Shanghai, China

Houyong Ma