Large-Surface-Area Nanowall SnS Films Prepared by Chemical Bath Deposition

Abstract

The growth of tin sulfide (SnS) films with large surface area have been accomplished. A uniform nanowall SnS thin film over the entire substrate was achieved by using an economic chemical bath deposition method and observed by scanning electron microscopy. Microstructure, phase confirmation, and optical properties were investigated. X-ray diffraction pattern and transmission electron microscopy revealed that the tin sulfide film by chemical bath deposition exhibited polycrystalline orthorhombic structure. The optical absorption coefficient was high, more than , which is beneficial for a photovoltaic device. An optical indirect bandgap of SnS film was obtained to be . The effect of SnS film thickness on bandgap was also investigated. When the thickness was small, in the range of less than , the bandgap of SnS film increased with the increase of thickness. When the thickness was large, in the range of more than , the bandgap slightly decreased with the increase of thickness. The photoconductivity increased with the increase of film thickness for the nanowall SnS thin films.