Realization of High Photovoltaic Efficiency Devices With Sb₂S₃ Absorber Layer

This study investigates the impact of substrate temperature ( $\textit{T}_{\text{sub}}\text{)}$ on the structural, optical, and electrical properties of dual ion beam sputtering (DIBS)-grown Sb $_{\text{2}}$ S $_{\text{3}}$ thin films. $\textit{T}_{\text{sub}}$ has been systematically varied from room temperature (RT) to 300 $^{\circ}$ C. X-ray diffraction (XRD) investigation demonstrates the high crystalline quality of the Sb $_{\text{2}}$ S $_{\text{3}}$ thin films, revealing an orthorhombic structure with a characteristic diffraction peak corresponding to (211) plane observed at 28.4 $^{\circ}$ . The field-emission scanning electron microscopy (FESEM) images illustrate that the growth of thin film at 200 $^{\circ}$ C yields the largest grain size, measuring 62 nm, along with homogeneous and distinct grain morphology. In-depth optical analysis using spectroscopic ellipsometry (SE) with a three-layer model fitting technique indicates a high absorption coefficient (10 $^{\text{5}}$ cm $^{-\text{1}}\text{)}$ in the UV–VIS spectral region, while the films exhibit direct bandgap values ranging from 1.6 to 2.3 eV. The electrical resistivity and mobility of the Sb $_{\text{2}}$ S $_{\text{3}}$ films are evaluated at RT through four-probe Hall measurements, confirming the stable, repeatable, and reliable p-type electrical conductivity. In addition, the analysis of the p-Sb $_{\text{2}}$ S $_{\text{3}}$ /n-Si junction demonstrates an exceptional rectification ratio of 100 at $\pm$ 1 V. Furthermore, the experimental results are incorporated into the modeling and numerical analysis of Sb $_{\text{2}}$ S $_{\text{3}}$ heterojunction solar cells using the solar cell capacitance simulator (SCAPS) software. This analysis has identified the optimal thickness for the Sb $_{\text{2}}$ S $_{\text{3}}$ absorber layer to be 1.5 $\mu $ m, resulting in the highest efficiency of 16.39% along with open-circuit voltage ( $\textit{V}_{\text{oc}}\text{)}$ of 0.949 V, short-circuit current ( $\textit{J}_{\text{sc}}\text{)}$ of 24.73 mA/cm $^{\text{2}}$ , and fill factor (FF) of 69.81%.