A high-quality four-junction space solar cell and its preparation method

Abstract

The invention discloses a high-quality four-junction space solar cell and a preparation method thereof, comprising a Ge substrate, and a Ge sub-cell, a GaInP nucleation layer, and a GaInAs buffer are sequentially arranged on the Ge substrate according to a layered stack structure from bottom to top. layer, first tunneling junction, compositionally graded buffer layer, DBR reflective layer, GaInAs subcell, second tunneling junction, AlGaInAs subcell, third tunneling junction, AlGaInP subcell; AlGaInAs subcell and AlGaInP subcell A depletion layer is formed between the base region and the emitter region, and the base region and the emitter region have a graded bandgap structure. By introducing a graded bandgap structure into the Al-containing subcell, the material quality of the depletion layer is improved and the photogenerated carriers are reduced. The minority carrier recombination rate is mainly generated in the region, which improves the collection efficiency of photogenerated carriers. At the same time, the graded band gap has the effect of assisting the back field, so that the photogenerated carriers far away from the depletion layer drift to the depletion layer. The Al composition makes the effective band gap of the Al-containing subcell wider, which is beneficial to obtain higher open-circuit voltage.

Description

technical field [0001] The invention relates to the technical field of solar photovoltaic power generation, in particular to a high-quality four-junction space solar cell and a preparation method thereof. Background technique [0002] Forward-mismatched AlGaInP / AlGaInAs / GaInAs / Ge four-junction solar cells are based on forward-mismatched triple-junction cells. By developing large-mismatched GaInAs sub-cells, introducing high Al composition AlGaInAs sub-cells, and wide-bandgap AlGaInP sub-cells, not only optimized It not only improves the comprehensive utilization of the solar spectrum, but also improves the utilization efficiency of the single-band spectrum, and finally realizes the improvement of the overall performance of the product, and obtains a forward-mismatched four-junction solar cell with an efficiency of more than 34%. At the same time, compared with the three-junction battery, the radiation resistance of the four-junction battery is significantly improved, especia...

AI Technical Summary

Problems solved by technology

Under the current production conditions, the existence of impurities such as water and oxygen is difficult to completely eliminate, and in the development of four-junction batteries, the application of high-alumina component materials is unavoidable

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