Investigation of the photovoltaic performance of n-Zno/n-CdS/p-Cu₂ZnSnS₄ solar cell

The semiconducting thin film solar cell based on Cu₂ZnSnS₄ (CZTS) materials is considered as a promising candidate for very large-scale application due to high absorption coefficient and low cost. In this study, the performances of n-ZnO/n-CdS/p-CZTS solar cells were numerically simulated using the AFORS-HET software. The influences of double-graded bandgap and thickness of CZTS layer on the performances of the solar cell were investigated. The calculated results show that double-graded bandgap structure can greatly optimize the conversion efficiency of CZTS thin film solar cell. The optimal dual gradient structure is 1.4 eV-1.3 eV-1.5 eV, the optimal thickness ratio is 11:1, and the conversion efficiency could be 26.63%. The results of this study can serve as a guide in fabricating CZTS solar cell.