Numerical modeling and analysis of FeS2-based solar cell employing CuBi2O4 as back surface field layer

This research explores a novel design for thin-film solar cells, featuring FeS2 as the absorber layer, CuBi2O4 as the back surface field (BSF) layer, and GaAs as the buffer layer. We carefully evaluate the solar cell's performance using the SCAPS 1D simulator, including layer thickness, doping levels, and FeS2 and CuBi2O4 defect concentrations. Our n-GaAs/p- FeS2 solar cell exhibits a notable power conversion efficiency (PCE) of 19.19%, a J(SC) of 46.34 mA/cm(2), a V-OC of 0.517 V, and an FF of 80.02%. However, our study delves deeper into the intriguing introduction of the CuBi2O4 BSF layer as a second absorber layer in solar cells. This modification boosts PCE to 33.29%, J(SC) (49.64 mA/cm(2)), and V-OC (0.843 V) while retaining a high FF of 79.58%. The proposed FeS2/CuBi2O4 structure represents an impressive 73.49% improved cell performance compared to the conventional single junction FeS2-based solar cell. Due to the excellent band alignment in the dual-heterojunction arrangement, the efficiency increases significantly. Our study advances FeS2 solar cell optimization, showing the promise of innovative material combinations for photovoltaic technology. Our findings also highlight the importance of adding second absorber layers to improve solar cell efficiency and contribute to sustainable energy.