Boosting solar cell performance: optimization of WS₂ absorber with Cu₂O HTL & ZnSe ETL using SCAPS-1D simulation

Thin-film photovoltaic materials like WS₂ offer abundant, low-cost, transparent energy sources. WS₂ boasts high carrier mobility, a superior optical absorption coefficient over 105 cm^− 1, a favorable band gap of 1.3 eV, and non-toxic properties, making it a promising photon absorber. Previous studies explored various WS₂-based solar cell designs for enhanced efficiency. This study investigates an ultrathin WS₂ solar cell with Cu₂O as the hole transport layer (HTL) and ZnSe as the electron transport layer (ETL). The traditional toxic CdS-based buffer structure is proposed to replace a ZnSe-based alternative. Results show significant enhancements in electrical characteristics, with a maximum conversion efficiency of 31.99% at the optimal bandgap, with a V_OC of 1.03 V, a J_SC of 35.26 mAcm^− 2, and an FF of 88.08% with Cu₂O HTL. On the other hand, we have got V_oc of 0.97 V, J_sc of 35.02 mA/cm², FF of 87.08%, and PCE of 29.72% without HTL. This suggests the potential of the proposed structure for improving thin-film solar cell performance.