Electrochemical synthesis of SnS thin films for photoelectrochemical cells

Abstract

Tin Sulphide (SnS), a layered semiconducting material which finds wide applications in optoelectronic devices and window material for heterojunction solar cell. This paper reports on the materials properties of thin films of SnS prepared by electrodeposition and brush plating. Brush plating is an electroplating process usually adopted to coat large area thin metal or alloy film. The films of 0.6 - 1.0 μm and 1.0 - 2.5 μm thickness were prepared by electrodeposition and brush plating respectively. X-ray diffraction studies showed that the as prepared films of both techniques revealed polycrystalline nature of the films and the lattice parameter values are: a = 0.403 nm; b = 1.145 nm; and c = 0.399 nm. The surfaces were analyzed by electron spectroscopy for chemical analysis (ESCA) and Scanning Electron Microscopy (SEM) for surface morphology. The band gap, refractive index and extinction coefficient values were estimated from the optical studies in the wavelength region of 400-1500 nm. The adhesion of the films prepared by brush plating was found to be excellent. Photoelectrochemical (PEC) solar cells were fabricated using SnS photoelectrodes. Capacitance-Voltage (C-V) studies revealed the p-type nature of all the films. The flat band potentials were 0.52 V and 0.47 V respectively. The quality of the films prepared by electrodeposition and brush plating are compared.