A kind of multi-junction solar cell with metamorphic buffer layer and fabrication method thereof

Abstract

The present application discloses a multi-junction solar cell with a metamorphic buffer layer and a manufacturing method. By reducing the thickness of each layer in the composition-graded layer in a set direction, the thickness of the composition-graded layer is reduced. With the reduction of nanohardness and the increase of epitaxial thickness, the probability of dislocation release is reduced, and the probability of dislocation extending to the active area of ​​the battery to affect performance is reduced. Alternatively, setting the mismatch degree between layers in the composition-graded layer to decrease sequentially can further reduce the probability of dislocation release in the composition-graded layer as the nanohardness decreases and the epitaxial thickness increases, reducing the dislocation Chances of wrong extensions into the active area of ​​the cell affecting performance. That is to say, the multi-junction solar cell of the present application makes the distribution of dislocation density more uniform throughout the metamorphic buffer layer, which can reduce the interaction between dislocations and reduce the TDD of line dislocation defects caused by this interaction.

Description

technical field [0001] The invention relates to the technical field of solar cells, more specifically, to a multi-junction solar cell with a metamorphic buffer layer and a manufacturing method. Background technique [0002] Solar cells convert solar energy directly into electricity and are the most efficient form of clean energy. III-V compound semiconductor solar cells have the highest conversion efficiency in the current material system, and have the advantages of good high temperature resistance and strong radiation resistance. They are recognized as a new generation of high-performance and long-life space main power supplies. / Ge lattice-matched triple-junction cells have been widely used in the aerospace field. [0003] However, the current density of the traditional lattice-matched triple-junction cell top cell GaInP and middle cell In0.01GaAs is much smaller than that of the bottom cell Ge, which does not make full use of the solar spectrum and limits the improvement...

AI Technical Summary

Problems solved by technology

However, both the increase of the In composition and the increase of the Al composition will lead to a decrease in the nanohardness of the material, a decrease in the critical thickness, and it is easier to generate stress caused by dislocation release mismatch.

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