Chemical Synthesis and Characterization Study of Nanocrystalline and Coral Rock-Like Kasterite Cu2ZnSnS4 (CZTS) Thin Films

The Cu2ZnSnS4 (CZTS) thin film is a newly emerging semiconductor material in the thin film solar cell industry. The CZTS is composed of economical, common earth-abundant elements. It has advantageous properties like a high absorption coefficient and the best band gap. Here we have applied a low-cost chemical bath deposition technique for the synthesis of CZTS at low temperature, acidic medium and its characterization. The films were characterized by different techniques like X-ray diffraction, Raman, SEM, Optical absorbance, electrical conductivity and PEC study. The X-ray diffraction and Raman scattering techniques were utilized for structural study. The XRD reveals the kasterite phase and nanocrystalline nature of CZTS thin films. These results and their purity were confirmed further by advanced Raman spectroscopy with a 335 cm-1 major peak. The crystallite size was found to be 50.19 nm. The optical absorbance study carried out by use of UV-visible spectroscopy analyses its band gap near about 1.5 eV and its direct type of absorption. The electrical conductivity technique gives a p-type of conductivity. The scanning electron microscopy (SEM) study finds its rock-like unique morphology. The EDS technique confirms its elemental composition and its fair stoichiometry. The analysis of PEC data revealed power conversion efficiency-PCE to 0.90%.