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

Abstract

Due to excellent optoelectronic properties, as well as low toxicity, inexpensiveness, and easy availability, the antimony chalcogenides (Sb2(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 Sb2(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 Sb2(S,Se)3 solar cells is systematically investigated. It is revealed that all the chosen narrow to wider bandgap‐based Sb2(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.