Light-emitting diode with novel P-type electron barrier layer structure and growth method

Abstract

The invention provides a light-emitting diode with a novel P-type electron barrier layer structure and a growth method. The LED epitaxy structure of the light-emitting diode comprises a substrate, a low-temperature GaN buffer layer, a GaN non doping layer, an N-type GaN layer, a multiple quantum well layer, a low-temperature GaN layer, a P-type InAlGaN electron barrier layer, a high-temperature P-type GaN layer and a P-type contact layer which are sequentially arranged from bottom to top. According to a P-type InyAlxGal-x-yN electron barrier layer of the composite structure, In components are added, and the InyAlxGal-x-yN lattice constant is adjusted, so that lattice matching between the P-type GaN layer and the multiple quantum well layer can be achieved, dislocation density is reduced, lattice quality is improved, and expected energy band gap value and energy band drift rate are obtained. Consequently, electron leakage is effectively reduced, and the injection rate of holes is improved. Moreover, a gradually-changing structure of the P-type InAlGaN drift rate is designed, and the restriction to hole vertical migration is avoided, so that the injection efficiency of holes is improved, and the light-emitting efficiency of a GaN-based light-emitting diode is further improved.

Description

technical field [0001] The invention relates to the technical field of preparation of Group III nitride materials, in particular to a light-emitting diode with a novel P-type electron blocking layer structure and a growth method. Background technique [0002] Light Emitting Diode (LED, Light Emitting Diode) is a semiconductor solid-state light-emitting device, which uses a semiconductor PN junction as a light-emitting material, and can directly convert electricity into light. Group III nitrides represented by gallium nitride are wide-bandgap semiconductor materials with direct bandgap, which have excellent properties such as high electron drift saturation velocity, good thermal conductivity, strong chemical bond, high temperature resistance and corrosion resistance. Its ternary alloy indium gallium nitride (InGaN) band gap is continuously adjustable from 0.7eV indium nitride (InN) to 3.4eV gallium nitride (GaN), and the emission wavelength covers the entire region of visible...

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Problems solved by technology

[0004] However, the current technology still has the following problems: 1) The more obvious the effect of the P-type electron blocking layer on electron blocking, the greater the drop in hole injection efficiency, that is, the higher the electron blocking efficiency, the lower the hole injection efficiency; at the same time, due to the Al group The lattice mismatch between the existing AlGaN electron blocking layer and the P-type GaN layer and the multi-quantum well layer is relatively large; 2) The current Al composition between the P-type AlGaN layer and the P-type GaN layer is an abrupt structure , that is, when switching to growing P-type AlGaN, the quantitative Al composition is directly introduced and remains unchanged

Although the large polarization difference at the heterointerface between the P-type AlGaN layer and the P-type GaN layer will induce two-dimensional hole gas to promote the lateral movement of holes, but the vertical confinement effect of two-dimensional hole gas on carriers is also enhanced so that holes accumulate at the heterointerface, resulting in a reduction in the number of holes migrating to the quantum well region

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