Effect of Annealed and Non-Annealed Inorganic MnS Hole-Transport Layer for Efficient Sb₂(S,Se)₃ Solar Cells: A Theoretical Justification

Due to excellent optoelectronic properties, as well as low toxicity, inexpensiveness, and easy availability, the antimony chalcogenides (Sb-2(S,Se)(3)) have emerged as promising and attractive light-harvesting materials for efficient inorganic solar cells. However, poor stability and the high cost of the conventional organic hole-transport layer (HTL, Spiro-OMeTAD) create room to find alternative low-cost, stable inorganic HTL materials. In that perspective, experimentally thermally evaporated low-cost inorganic manganese sulfide (MnS) semiconductor is an excellent choice for the HTL with/without post-annealing treatment. Therefore, herein, initially, an experimental HTL-free Sb-2(S,Se)(3) device is simulated, including four other different bandgap-based devices using SCAPS-1D software. Later, the effect of annealed and non-annealed MnS-HTL for all five Sb-2(S,Se)(3) solar cells is systematically investigated. It is revealed that all the chosen narrow to wider bandgap-based Sb-2(S,Se)(3) devices display enhanced photovoltaic performances after adding the MnS-HTL, specifically the annealed MnS-HTL. Due to enhanced energy level alignment and the hole transport between the absorber/HTL interfaces, the narrow-bandgap device presents higher power conversion efficiency, gets enriched from 8.3% (initial HTL-free device) to 12.1% (non-annealed MnS-HTL device) and 12.7% (annealed MnS-HTL device), and proves that annealed MnS-HTL is a feasible substitute for other HTLs.