Investigations on the Properties of Nanostructured Mg-Doped Sn2S3 Thin Films towards Photovoltaic Applications

This paper reports the synthesis, crystal structure, surface morphology, optical and electrical properties of Mg-doped Sn2S3 thin films deposited by spray pyrolysis technique. All the films exhibit orthorhombic crystal structure with a (211) preferential orientation. Crystallite size calculations based on the Debye-Scherrer formula indicated that the Sn2S3 crystallite size increases with Mg content from 27.97 nm to 33.58 nm. Scanning electron microscopy images showed that all the films were very smooth composed of nanoneedle and nanoplate shaped grains. The band gap energy of the films exhibits a blue shift from 1.94 eV to 2.09 eV with increase in Mg concentration. Resistivity values of the undoped and Mg-doped Sn2S3 films were found to be in the order of 0.1 Omega cm. From the obtained results it is observed that the Sn2S3 film coated with 2 wt% Mg concentration exhibits better physical properties.