Comprehensive characterization of silver-doped antimony selenide films: linking silver incorporation to photovoltaic suitability

Abstract Antimony selenide (Sb 2 Se 3 ) has been extensively studied as a high-potential absorber semiconductor material for solar energy conversion because of its exceptional optoelectronic characteristics, earth-based constituents, and non-toxic nature. Despite its potential, the energy conversion of Sb 2 Se 3 -based thin-film photovoltaics remains limited, necessitating further optimization of the absorber layer through strategic doping. In this study, silver (Ag)-doped Sb 2 Se 3 thin films were successfully synthesized via a sequential process involving magnetron sputtering of Sb 2 Se 3 , thermal evaporation of a thin Ag layer, and subsequent post-annealing for varying durations. The structural, morphological, and optical impacts of Ag incorporation were systematically investigated. X-Ray Diffraction (XRD) analysis confirmed that Ag was successfully integrated into the Sb 2 Se 3 lattice by substituting antimony (Sb) sites without the formation of any secondary metallic or impurity phases. Optical characterization demonstrated a notable reduction in the bandgap from 1.33 eV to 1.19 eV upon silver incorporation, effectively extending the visible light absorption range. The elemental composition of the sample was first validated using Energy Dispersive Spectroscopy. Subsequently, X-Ray Photoelectron Spectroscopy was employed to confirm that Ag atoms migrate from the surface into the bulk lattice during extended annealing. These findings highlight that Ag-doped Sb 2 Se 3 films prepared via sequential deposition offer a viable and effective route for enhancing the performance of next-generation sustainable photovoltaic devices.