Preparation method for GaInP/GaAs dual-junction solar cell

Abstract

The invention discloses a preparation method for a GaInP / GaAs dual-junction solar cell. The preparation method comprises: step A, a first transition layer GaP grows on a substrate; step B, a second transition layer Ga(1-x)InxP grows on the first transition layer GaP; step C, a GaAs bottom cell grows on the second transition layer Ga(1-x)InxP; and step D, a GaInP top cell grows on the GaAs bottom cell, wherein the content of indium in the second transition layer Ga(1-x)InxP is adjusted to realize matching of the lattice constant of the second transition layer Ga(1-x)InxP with the lattice constant of the GaAs bottom cell. According to the preparation method, the GaP and the Ga(1-x)InxP are used as transition layers and transition of the lattice constant of the second transition layer Ga(1-x)InxP to the lattice constant of the GaAs bottom cell is realized, so that lattice constant matching is realized and thus an objective of growing and preparing a GaInP / GaAs dual-junction solar cell is achieved.

Description

technical field [0001] The invention belongs to the field of solar cells, and in particular relates to a preparation method of a GaInP / GaAs double-junction solar cell. Background technique [0002] Environmental and energy requirements make new energy technologies, including solar energy efficient power generation, more and more important. As a forward-looking and strategic new clean energy technology that supports the sustainable development of my country's national economy, high-efficiency solar power generation technology is listed as a key support and priority development direction in the national medium and long-term scientific and technological development plan. Multi-junction III-V compound semiconductor solar cells use various semiconductor materials with different bandgap widths to absorb the part of sunlight that matches their bandgap widths, thereby achieving broad-spectrum absorption of sunlight. At present, the efficiency of double-junction cells has reached Ex...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two main methods for making III-V multi-junction cells on Si substrates. One is to grow GaInP / GaAs double-junction cells on GaAs substrates first, and then bond the cells to Si substrates. It is relatively complicated, and the use of wet etching will cause damage to GaAs; in addition, the preparation process for bonding and the process of stripping the GaAs substrate must have high production capacity and equipment to effectively reduce costs

The second is to directly grow double-junction cells on the Si substrate. The direct growth method reduces the cumbersome process preparation, but there is a 4% difference in lattice constant between Si and GaAs. Usually, the buffer layer transitions to GaAs, and the first growth and Si Lattice close to GaP then through graded composition GaAs y P 1-y , gradually transitions the lattice to the lattice constant of GaAs; however, GaAs with a graded composition y P 1-y Difficult to control the accuracy of composition during growth due to the presence of two V sources

Images