Structure and growth method of green LED chip epitaxial layer

Abstract

Disclosed is a structure of a green-light LED chip epitaxial layer. The structure comprises a substrate; a GaN buffer layer growing on the substrate; a non-doped GaN layer growing on the GaN buffer layer; an N-type GaN layer growing on the non-doped GaN layer; a first step layer growing on the N-type GaN layer; a multiquantum well region growing on the first step layer; a second step layer growing on the multiquantum well (MQW) region; a P-type GaN layer growing on the second step layer; and an ohmic contact layer growing on the P-type GaN layer. According to the invention, through employing an InGaN barrier layer in the MQW region and adding step layer structures, the cavity injection efficiency is improved, the electron leakage is reduced, at the same time, the QCSE effect in a quantum well is reduced, the green-light LED luminescence efficiency is improved, and the droop effect is inhibited.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a structure and a growth method of a green LED chip epitaxial layer, which can be used in the manufacture of semiconductor photoelectric devices. Background technique [0002] Gallium nitride (GaN)-based green light-emitting diode (LED) is a semiconductor solid-state light-emitting device widely used in the field of display and lighting. The core part of its epitaxial structure is the InGaN / GaN multiple quantum well (MQW) region. The luminous efficiency of LED mainly depends on the structure and quality of the MQW region. Therefore, optimizing the MQW structure and improving the quality of MQW materials is the fundamental way to obtain high-brightness green LED devices. [0003] Traditional GaN-based green LEDs use a simple InGaN / GaN MQW structure as the active region, which is characterized by using GaN material as a barrier layer to confine carriers. The st...

AI Technical Summary

Problems solved by technology

The structure is simple and easy to prepare materials, but there is no distinction between the confinement of electrons and holes. Therefore, there are problems of low hole injection efficiency and high electron leakage, which leads to a significant decrease in the luminous efficiency of green LED devices under high current, that is, droop effect

In addition, due to the deep potential well of the green LED quantum well and the high content of In in the well, there is a large lattice mismatch between the InGaN well and the GaN barrier layer.

Due to the increase of the mismatch strain, a strong piezoelectric polarization effect will appear in the InGaN well layer, which will cause the enhancement of the quantum confinement Stark effect (QCSE), which will lead to a significant decrease in the luminous efficiency of the material.

In addition, the large lattice mismatch is also very likely to lead to lattice relaxation at the interface between the InGaN well and the GaN barrier layer, resulting in a large number of mismatch dislocations, which increases the probability of non-radiative recombination of carriers. Thereby further reducing the luminous efficiency of green LED

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