Multi-junction solar cells and methods of making the same

Abstract

A multi-junction solar cell, at least comprising a bottom sub-cell and a top sub-cell located on the bottom sub-cell. The top sub-cell is merely formed on a partial surface of the bottom sub-cell to reduce a light receiving area of the top sub-cell; and when light is incident onto the multi-junction solar cell, partial light is directly absorbed by the rest of the sub-cells under the top sub-cell, so as to reduce a current of the top sub-cell.

Description

technical field [0001] The invention belongs to the field of compound semiconductor solar cells, and in particular relates to a multi-junction solar cell structure and a preparation method thereof. Background technique [0002] A solar cell is a semiconductor device that uses the photovoltaic effect to convert solar energy into electrical energy. It is composed of a p-type and n-type semiconductor. When sunlight irradiates the device, the sunlight with energy greater than the energy gap of the semiconductor will be absorbed, causing the semiconductor device to generate electron-hole pairs, which will form a current when it is turned on. [0003] figure 1 It is a spectrum map of solar radiation, the main wavelength distribution ranges from 0.3 microns of ultraviolet light to several microns of infrared light, converted into photon energy, from about 0.4 eV to 4 eV. In order to be able to absorb more sunlight energy, multi-junction solar cells have been proposed, which stack...

AI Technical Summary

Problems solved by technology

Although the bandwidth of energy absorption can be increased in this way, due to the stacking of semiconductor material layers with different energy gaps, the current density difference between the top solar cell and the bottom solar cell is too large, and this current mismatch will cause the entire The photoelectric conversion efficiency of the device is reduced, so how to reduce the current mismatch is an important issue

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