Ultrasound-assisted electrodeposition of SnS: Effect of ultrasound waves on the physical properties of nanostructured SnS thin films

Nanostructured SnS thin films were prepared using an electrochemical deposition method on fluorine doped tin oxide (FTO) substrate from aqueous solution containing 2 mM SnCl2 and 16 mM Na2S2O3. The pH, temperature, time, and deposition potential (E) of the solution were remained at 2.10, 60 degrees C, 30 minutes and -1 V, respectively. The ultrasonic waves were applied to synthesize ultrasound-assisted electrodeposited SnS thin film. The characterization of deposited thin films was carried out by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), room temperature photoluminescence (PL) and UV-Vis spectroscopy. The deposited SnS nanostructures were polycrystalline with orthorhombic structure. By applying ultrasonic waves, the crystalline quality was decreased. The FESEM images revealed that the ultrasonic waves are responsible for the changes in the morphology of the SnS nanostructures. Also by applying ultrasonic waves, more thin planes were created which led to formation of two dimensional (2D) SnS. The PL spectra of the ultrasound-assisted electrodeposited SnS film showed a red shift compared to the electrodeposited SnS. The optical bandgap energy (E-g) of the ultrasound-assisted electrodeposited SnS decreased from 1.5 eV to 1.45 eV. In addition, the ultrasound-assisted electrodeposited SnS has greater conversion efficiency of solar cell than that of the electrodeposited SnS. (C) 2016 Elsevier B.V. All rights reserved.