Tin sulfide: Reduced graphene oxide nanocomposites for photovoltaic and electrochemical applications

Abstract

Nanocomposite thin films of tin sulfide (SnS) with graphene oxide (GO) and reduced graphene oxide (rGO) were prepared by spray deposition of tin sulfide nanocolloids mixed with graphene oxide. SnS nanocolloidal suspensions were synthesized by liquid phase pulsed laser ablation of a SnS target in isopropyl alcohol and dimethyl formamide. Spherical morphology and orthorhombic crystalline structure of the nanoparticles were determined by transmission electron microscopy. Graphene oxide was synthesized through a chemical pathway (Marcano's method) and was mixed with SnS nanocolloid. Thin films were deposited by spraying SnS nanocolloid as well as the GO mixed SnS on heated substrates. The thin films were post-annealed under vacuum to form reduced graphene oxide. Structure, morphology and optoelectronic properties of thin films formed at various conditions were determined by different techniques. Scanning electron micrographs showed porous film surface with GO/rGO net-like structures embedded in SnS nanoparticles. Photocurrent measurements at different illumination wavelengths and cyclic voltammetry using SnS:rGO as working electrodes showed improvement in the properties of graphene oxide incorporated SnS. A solar cell was fabricated using SnS:rGO thin film and the results obtained are promising.