Electrodeposited SnS film for photovoltaic applications

Abstract

SnS film has been produced by electrodeposition technique onto ITO (indium-tin-oxide) coated glass substrates using aqueous solution containing SnCl2 and Na2S2O3. The pH of the solution was adjusted to 1.8 by drop-wise addition of 0.1 M HCl before the deposition. The SnS films were electrodeposited at constant potential value (−1.0 V relative to the saturated calomel electrode) in this study. The electrodeposition was carried out at 20 °C under constant stirring at 60 rpm in the bath. The deposition time was 30 min. The deposited film was uniform, well adherent and dark brown in colour. The SnS film has been characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The sample is polycrystalline in nature with orthorhombic phase having (101) and (040) preferential orientations. The crystallite size, texture coefficient, lattice parameters, strain and dislocation density were estimated from XRD results. Surface morphological studies were carried out by using Field Emission Scanning Electron Microscopy (FESEM). The band gap of the SnS film has been studied using the optical absorbance measurement as a function of wavelength between 200 and 3000 nm. The direct band gap of the sample is calculated to be 1.1 eV. The conductivity type of the sample was determined as p-type by using the Hall effect measurement. The Hall mobility of the sample had also been measured with temperature by means of the Hall effect.