A high-efficiency solar cell for double-sided use and a preparation method thereof are provided

Abstract

A high-efficiency solar cell for double-sided use and a preparation method thereof are disclosed. A metal organic chemical vapor deposition technology or molecular beam epitaxy growth technology is adopted to sequentially grow a first GaAs buffer layer, first tunnel junction, GaAs sub-cell, second tunnel junction, GaInP sub-cell and n-type GaAs cap layer with high doping concentration on the uppersurface of a GaAs substrate, a second GaAs buffer layer, GaInNAs sub-cell and n-type GaAs cap layer with high doping concentration are sequentially grown on the lower surface of the GaAs substrate, GaInP/GaAs/GaInNAs three-junction battery are obtained, and the upper and lower surfaces of the GaInP/GaAs/GaInNAs three-junction battery are photoetched, an antireflection film is deposited, electrodes are prepare and subsequent battery chips are manufactured; The invention can make the band gap structure of the battery more matched with the solar spectrum, improve the overall open-circuit voltageof the GaAs multi-junction battery, absorb and utilize the incident light on the back of the battery, and finally improve the photoelectric conversion efficiency of the battery.

Description

technical field [0001] The invention relates to the technical field of solar photovoltaic power generation, in particular to a double-sided high-efficiency solar cell and a preparation method thereof. Background technique [0002] Multi-junction cascaded solar cells are composed of a variety of semiconductor materials with different bandgap widths, which are arranged in order according to the bandgap width of the materials from wide to narrow and from top to bottom, which can selectively absorb and convert different bands of the solar spectrum. Improve the photoelectric conversion efficiency of solar cells. GaInP / GaInAs / Ge triple-junction solar cells are the mainstream structure of gallium arsenide multi-junction solar cells. The overall cell structure maintains lattice matching, the band gap structure is 1.9 / 1.40 / 0.67eV, and the conversion efficiency can reach 30% under the AM0 spectrum . However, for the solar spectrum, the bandgap combination of this triple-junction cel...

AI Technical Summary

Problems solved by technology

However, for the solar spectrum, the bandgap combination of this triple-junction cell is not optimal due to the large bandgap gap between the GaInAs subcell and the Ge subcell, and the solar spectrum absorbed by the Ge bottom cell under this structure The energy absorbed by the middle battery and the top battery is much more, so the short-circuit current of the Ge battery can be close to twice that of the middle battery and the top battery, resulting in a great waste of the solar spectrum in the infrared band, and the utilization efficiency of the solar spectrum is not high.

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