Effect of H2 annealing on SnS thin films grown by thermal evaporation and their transfer characteristics with Ti, W, and Mo electrodes

Abstract

Tin monosulfide (SnS) is a promising absorber layer material in solar cell devices. In addition to its outstanding electrical and optical properties, SnS does not contain rare heavy-metal atoms. Thus, many researchers have focused on fabricating highly efficient SnS-based solar cell devices. However, the effect H2 annealing on thermally evaporated SnS thin films and their transfer characteristics with various metals have not been thoroughly studied yet. In this paper, SnS was deposited by thermal evaporation and annealed in a H2 gas ambient at 400 °C. X-ray diffraction (XRD), scanning electron microscopy, Hall measurements, and Rutherford backscattering spectrometry revealed that our SnS thin films were single-phase with enhanced physical and electrical properties. Furthermore, the electrical band structure of SnS was investigated by UV-visible and ultraviolet photoelectron spectroscopy analyses to predict the electrical band alignment when in contact with Ti, W, and Mo electrodes. XRD and atomic force microscopy analysis confirmed that SnS was well grown on these metal electrodes. Finally, SnS with Mo electrodes showed the most conductive transfer characteristics. © 2021