Synthesis of highly dispersed Cu2ZnSnS4 nanoparticles by solvothermal method for photovoltaic application

Monodisperse and nearly stoichiometric quaternary Cu2ZnSnS4 (CZTS) nanoparticles were synthesized using a low-cost and high reproducibility method without vacuum system or protective atmosphere. The reaction vessel is a stainless steel autoclave with a Teflon liner under magnetic stirring. The structure, stoichiometric composition and morphology of the as-synthesized CZTS nanoparticles were characterized by means of X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectra (EDS), scanning electronic microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM). All the above confirmed the purity and composition of CZTS nanoparticles. UV–vis absorption spectroscopy measurement indicated that the band gap of as-synthesized CZTS nanoparticles was 1.54 eV, which was near the optimum value for photovoltaic solar conversion in a single-band-gap device.