Simulating the Effect of Inserting Sb₂S₃ as Hole Transport Layer on SnS-Based Thin-Film Solar Cells

Tin sulfide (SnS) absorbers have received considerable attention for their application in highly efficient, inexpensive, and stable thin-film solar cell (TFSC) technology. The present study reports the performance enhancement in the SnS-based TFSC by incorporating an antimony sulfide (Sb₂S₃) as a hole transport layer (HTL) between the absorber and rear electrode. The SCAPS-1D (solar cell capacitance simulator in one dimension) was utilized to modify the conventional SnS solar cell and to investigate the performance parameters of the proposed heterojunction nickel (Ni)/antimony sulfide (Sb₂S₃)/SnS/cadmium sulfide (CdS)/fluorine-doped tin oxide (FTO)/aluminum (Al) solar device. Different HTLs including Sb₂S₃, copper iodide (CuI), and nickel oxide (NiO_x) were investigated to determine the most effective HTL for SnS solar cells. The performance of the proposed TFSC was also examined by varying the thickness, carrier concentration, bulk defect density, temperature, metal work function, and cell resistance. Power conversion efficiency of 30.47% with open-circuit voltage (V_oc) of 1.02 V, short-circuit current density (J_sc) of 34.34 mA/cm², and fill factor (FF) of 87.25% were achieved for the optimized heterojunction SnS cell structure. These findings suggest that the low-toxicity Sb₂S₃ can be effectively employed as an HTL in highly efficient and low-cost SnS TFSCs.