Electrical and Optical Characterisation of CZTS Thin-Film for Sensing Applications

Abstract

The low-cost, earth abundant kesterite copper-zinc-tin-sulfide (CZTS) is the most desirable material for the upcoming sustainable energy, sensors and energy storage as well as generation. However, the research on the material was hindered due to the instability of the zinc and copper in the quaternary phase, thus, resulting in secondary complex phase with defects. This led to the structural inhomogeneity, challenges in the repeatability of the synthesis procedure and degradation (especially) in the efficiency of the solar cell. Therefore, synthesis of CZTS in right phase and purity (without any stoichiometric imbalance as well as secondary phases and defects) is a challenge to overcome. Moreover, due to the presence of copper and zinc, it is an interesting material for the scientific community as gas sensor. In this report we have synthesized CZTS through chemical synthesis and examined a spin coated CZTS thin film for probable sensing application at room temperature. We utilized the CZTS thin-film for room temperature gas sensing of the volatile organic compound (ethanol) at 68 PPM. In addition, the Phase purity of the film was confirmed by the X-ray diffraction. While, the optical characterization of the film was investigated by the UV-Spectrometer. Thickness of the film was confirmed by atomic force microscopy and the electrical characterization of the film was done by Kiethley 2420.