Analytical model for studying the role of ZnS-doped CdS on the performance of CZTSSe solar cells

This study focuses on thin-film structures made of ITO, CdS, ZnS, CZTSSe, and Mo (i.e., ITO/CdS:ZnS/CZTSSe/Mo) for solar cell applications. The effect of ZnS content on the performance of this cell has been theoretically investigated. The optical losses caused by reflection at various interfaces and absorption in ITO and CdS:ZnS layers have been calculated using the current structure's experimental data. The losses due to charge carrier recombination at the front and back surfaces of the CZTSSe absorber have been calculated using the absorber layer and depletion region parameters. It was discovered that increasing the ZnS content causes more photons to enter the absorber layer, causing the short-circuit current density to increase. Under consideration of optical and recombination losses, a maximum efficiency of about 13.75%, a fill factor of 81.6%, and an open-circuit voltage of 808 mV were obtained for ZnS-content = 0.5.