Variations in structural and optoelectronic features of thermally co-evaporated SnS films with different Sn contents

SnS films with different Sn contents were fabricated by thermal co-evaporation. The variation in structures, optical and electrical properties of SnS with different Sn contents was systematically investigated. The prepared films were characterized by X-ray diffraction, field emission scanning electron microscopy , and energy dispersive spectroscopy analysis. An excess of Sn can result in a change of the SnS semiconducting film from p-type to n-type. The SnS films showed band gaps in the range of 1.25–1.57   eV and high mobilities of 7.29   cm 2 /V   ∙   s, indicating suitability for application in photovoltaic cells . The photoelectric conversion efficiency (PCE) of the heterojunction solar cell was 1.26% with a open circuit voltage ( V OC ) of 0.153   V and a short circuit current density ( J SC ) of 29.61   mA/cm 2 .