Performance Analysis of CdS-Free, Sb2Se3/ZnSe p-n Junction Cells with Various Hole Transport Layers and Contacts

Sb2Se3, a promising thin-film photovoltaic (TFPV) absorber material known for its non-toxic nature, abundance on Earth, and stability has the inherent limitations of low doping density of 10(13) cm(-3) and poor carrier mobility of 1.5 cm(2) V-1 s(-1), leading to a low built-in potential and inefficient carrier collection. To address these challenges and enhance the built-in potential and carrier collection, an effective hole-transport layer (HTL), e.g. CdS, which contains toxic components is used. A less-toxic alternative is explored: ZnSe as the electron-transport layer (ETL) to mitigate this issue. In this study, the performance is evaluated of Sb2Se3/ZnSe solar cells using six different HTLs (CuSCN, MoSe2, NiO, Spiro-OMeTAD, SnS, MoOx) through the utilization of the SCAPS-1D modeling tool. The HTL plays a critical role in improving the effectiveness of the built-in potential, enhancing carrier collection, and suppressing back surface recombination. The analysis involves varying the thickness and doping concentration of the absorber, buffer, and HTLs, and exploring the impact of temperature, series and shunt resistance, and the metal work function of the back contact. Among the tested devices, the one with NiO as the HTL demonstrates the highest efficiency, exhibiting a V-OC (open-circuit voltage) of 0.81 V and a PCE (power conversion efficiency) of 24.07%.