Experimental, DFT, and SCAPS-1D Investigation of Sulfur-Incorporated Sb2Se3 Powders for Photovoltaic Applications.

Antimony selenide (Sb2Se3) is a promising photoabsorber material for photovoltaics (PVs) owing to its favorable properties, including a high absorption coefficient, an optimal bandgap, earth-abundant constituents, and low toxicity. In this study, sulfur (S)-incorporated Sb2Se3 powders were synthesized by substituting Se with S using a solid-state method. Structural, morphological, and optical analyses showed that increasing sulfur content widened the bandgap from 1.10 to 1.54 eV. Furthermore, DFT calculations supported the experimental bandgap trend. SCAPS-1D simulations indicated that higher bandgaps increase open-circuit voltage (Voc) but short-circuit current density (Jsc), with optimal performance at 1.362 eV. The simulated device achieved power conversion efficiency (PCE) of 24.31%, Voc of 0.899 V, Jsc of 32.92 mAcm-2, and FF of 82.06%. These results highlight sulfur incorporation as an effective approach for tuning the properties of Sb2Se3-based PVs.