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 cm2/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 (VOC) of 0.153 V and a short circuit current density (JSC) of 29.61 mA/cm2.