Cu2ZnSnS4 synthesized through a low-cost reflux method

Abstract

The chalcopyrite semiconductors belonging to the I2-II-IV-VI4 class are emerging as promising absorber materials for photovoltaic applications. Among them, Cu2ZnSnS4 (CZTS) has been gaining importance due to its high absorption coefficient and optimum band-gap. To make CZTS an economically viable alternative, in this study, the CZTS powder has been synthesized via a low-cost, environment-friendly reflux method. In the current method, the salts of the respective metals were taken as initial precursors, and thiourea was used as a precursor for sulfur. The stoichiometric amounts of the precursors were taken in distilled water and the solution was refluxed for 8 h. The products were filtered and washed with distilled water and ethanol consecutively. Phase identification was done using powder X-ray diffraction (given by the reference pattern JCPDS card no. #00-026-0575) and Raman spectroscopy analysis (corresponding Raman shifts for CZTS: 288 and 338 cm-1). The band gap of the compound was calculated from the UV-visible spectroscopy and found to be 1.4 eV.