Method for growing InGaAs film on GaAs substrate

Abstract

The invention discloses a method for growing an InGaAs film on a GaAs substrate, which comprises the following steps of: (1) cleaning the GaAs substrate; (2) pre-processing the GaAs substrate; (3) deoxidizing; (4) growing a GaAs buffer layer; (5) growing a low-temperature single-layer In0.6Ga0.4As big-mismatch buffer layer; and (6) growing an In0.3Ga0.7As epitaxial film, wherein the In0.6Ga0.4As big-mismatch buffer layer and the In0.3Ga0.7As epitaxial film both can be prepared by using the molecular beam epitaxial growth or metal organic vapor deposition technology. Various defects caused by mismatch stress can be lowered by the big-mismatch buffer layer. The prepared In0.3Ga0.7As epitaxial layer has lower defect density. The method has the advantages of simple buffer layer structure, simple and convenient epitaxial growth process, low defect density of the In0.3Ga0.7As epitaxial film, high crystal quality and the like.

Description

technical field [0001] The invention is applied in the fields of solar cells, high electron mobility transistors, photodiodes, photodetectors and the like, and particularly relates to a method for growing an InGaAs thin film on a GaAs substrate. Background technique [0002] With the rapid development of the solar photovoltaic power generation industry and market, and driven by the demand for space vehicle energy systems, photovoltaic technology has continuously made important breakthroughs: crystalline silicon, amorphous silicon, polycrystalline silicon solar cells, III-V compound semiconductor cells, II -Group VI compound semiconductor cells, etc. More and more solar cell technologies are maturing. At the same time, the corresponding photoelectric conversion efficiency continues to increase, making today's photovoltaic technology more and more widely used in space and on the ground. The rapid development of GaAs-based III-V compound semiconductor cell technology is the mos...

AI Technical Summary

Problems solved by technology

The ideal energy band matching of four-junction tandem solar cells is 1.8 / 1.4 / 1.0 / 0.67 eV. Through theoretical calculation, although 1eV GaInNAs material is suitable for the band gap and lattice size of the third-junction solar cell, the GaInNAs epitaxial material The low minority carrier lifetime severely limits the current density of four-junction tandem solar cells and becomes a key factor restricting the improvement of efficiency

[0005] At present, GaAs-based high-efficiency multi-junction tandem solar cells adopt buffer layer structures such as multi-layer composition gradient, composition jump, and composition inversion (such as figure 1 As shown), the buffer layers of these multilayer structures need epitaxial growth of multiple thicker buffer layers in the solar cell structure, the growth steps are cumbersome, and it is difficult to precisely control the composition, thickness, and crystal quality of each layer of material, so that Affects the final In 0.3 Ga 0.7 As film quality

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