Synthesis and Characterization of Chemically Sprayed Cu2FeSnS4 (CFTS) Thin Films: The Effect of Substrate Temperature

Abstract

In this study, Cu2FeSnS4 (CFTS) thin films were deposited on glass substrates at different temperatures of 250, 300, 350, 400, and 450 °C using the chemical pyrolysis technique. This work aimed to study the effect of substrate temperature on film properties. The film's structural properties were obtained via X-ray diffraction, Raman spectroscopy, and Field Emission Scanning Electron Microscopy (FESEM). The UV-Vis spectrum determined the optical properties; and the electrical properties were obtained through observation of the Hall effect. Analysis of XRD pattern showed that the CFTS thin films have a tetragonal structure with a main peak corresponding to the direction (112). Results of Raman spectroscopy displayed a unique peak at 318 cm-1, suggesting a quaternary compound of CFTS. The FESEM tests confirmed the presence of nanoparticles of various shapes and sizes. The CFTS films have a band gap of 1.77-1.92 eV and an absorption coefficient in the visible spectrum region higher than 104 cm-1, which confirms their use as an active layer in solar cells. The mea measurements of the Hall effect of the CFTS thin films showed a p-type conductivity for all films, with the maximum charge carrier density and mobility occurring at 400 °C, making them suitable for photovoltaic applications.