Contribution to the study of a CdS / CZTS-based solar cell with a gradual BSF layer

Thin-film solar cells are currently the subject of several research works aimed at achieving the best relationship between energy and cost efficiency. The objective of this work is to improve the performance of a thin film solar cell based on CdS / CZTS by introducing a gradual layer on the back surface (Back Surface Field) in order to reduce the recombination losses in the back face and therefore increase the efficiency of photovoltaic conversion. The results obtained show that the addition of a back surface field (BSF) has a remarkable influence on the characteristics and the electrical performance of the solar cell. This results into an improvement in the values of the short-circuit current and of the open-circuit voltage, as well as the conversion efficiency with acceptable quantities. This study shows that, for an absorbent layer thickness of 2.42 mu m, the BSF layer improves the photovoltaic conversion efficiency from 16.93% (cell without BSF) to 18.5% (for a cell with BSF).