Epitaxial structure for improving luminous efficiency and preparation method thereof

Abstract

The invention provides an epitaxial structure for improving luminous efficiency. The epitaxial structure for improving the luminous efficiency sequentially comprises a substrate, a first GaN (Gallium Nitride) buffer layer, a second GaN buffer layer, an N-type GaN layer, a multi-quantum well (MQW) structure, a light-emitting layer multi-quantum well structure, a p-type GaN layer, a p-type AlGaN (aluminium gallium nitride) layer, a p-type GaN layer and a p-type contact layer from the bottom up, wherein the multi-quantum well structure consists of n layers of InxGa1-XN / GaN multi-quantum wells; the widths, the depths and the barrier heights of the n layers of the multi-quantum wells increase layer by layer; the barrier widths of the n layers of the multi-quantum wells decrease layer by layer; the well widths increasing layer by layer and the barrier widths decreasing layer by layer form regular correspondence; and n is an integer in a range of 2-12. A preparation method of the epitaxial structure for improving the luminous efficiency can optimize concentration distribution of electrons, reduce stresses generated in growth processes of multi-quantum wells, reduce a quantum confined stark effect (QCSE) and improve the luminous efficiency of the multi-quantum wells.

Description

Technical field [0001] The invention belongs to the technical field of gallium nitride-based material preparation, and particularly relates to a method for improving the luminous efficiency of multiple quantum wells by a gallium nitride-based light-emitting diode. Background technique [0002] Group III nitride represented by gallium nitride is a wide bandgap semiconductor material with a direct band gap. It has high electron drift saturation speed, good thermal conductivity, radiation resistance, high temperature resistance, and good chemical stability and physical stability. The band gap of its ternary alloy indium gallium nitride (InGaN) is continuously adjustable from 0.7 eV indium nitrogen (InN) to 3.4 eV gallium nitride (GaN), and its emission wavelength covers the entire region of visible light and near ultraviolet light. Light-emitting diodes with InGaN / GaN multiple quantum wells as the active layer have outstanding characteristics such as high efficiency, environmental ...

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Problems solved by technology

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an epitaxial structure and a preparation method thereof for improving luminous efficiency, which are used to solve the huge built-in electric field and the The problem of reduced luminous efficiency of quantum wells caused by uneven carrier distribution

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