Multi-junction solar cell structure and preparation method thereof

Abstract

The invention discloses a multi-junction solar cell structure and a preparation method thereof. The multi-junction solar cell structure comprises a substrate and a plurality of sub-cells arranged on the substrate, and the plurality of sub-cells comprise an InGaAs sub-cell, the InGaAs sub-cell comprises a base region and an emitter region which are sequentially arranged in the direction away from the substrate; the emitter region comprises a first emitter region and a second emitter region which are sequentially arranged in the direction deviating from the base region, the base region and the first emitter region are InxGaAs layers, and the second emitter region is a GaInP layer, that is, the InxGaAs layer made of the same material as the base region is adopted in the front part, connected with the base region, of the emitter region; therefore, the energy band peak of the InGaAs / GaInP heterojunction deviates from a space charge region at a PN junction between the emitter region and the base region, so the influence of the energy band peak of the InGaAs / GaInP heterojunction on collection of photon-generated carriers in the emitter region to the base region is reduced, the collection efficiency is improved, and the conversion efficiency of the solar cell is improved.

Description

Technical field [0001] The present application relates to the field of solar cells, and more particularly to a multi-junction solar cell structure and a preparation method thereof. Background technique [0002] Solar batteries can convert solar energy into electrical energy, which is an effective cleaning energy form. The traditional solar cell is usually a silicon solar cell, but the silicon solar cell is compared to the absorption band of the sun spectrum, and therefore, the multi-junction solar cell will be born, and the multi-knot solar cell is a subell cell from different banned bands through tunneling However, each sub-battery absorbs different bands of the sun spectrum, which greatly improves the conversion efficiency of the solar cell. III-V compound multi-junction solar cells are the highest in the current material system, while having high temperature resistance, strong anti-irradiation capacity, and is recognized as a new generation of high-performance long life space ...

AI Technical Summary

Problems solved by technology

However, compared with the InGaAs / InGaAs homojunction, the InGaAs / GaInP heterojunction has an energy band peak at the PN junction interface and has a larger valence band step, which makes it difficult for the photogenerated carriers in the emission region to flow in the PN junction. Under the action of the built-in electric field, it crosses the peak of the energy band and collects it to the base region, forming an undesirable mismatch voltage, which affects the conversion efficiency of the solar cell

Images