A high-yield synthesis route to obtain phase-pure, highly crystalline Cu2ZnSnS4 (CZTS) nanocrystals with controlled Cu/(Zn+Sn) ratio is reported. The material properties were investigated to understand the effect of initial precursor concentrations on the stoichiometry of CZTS nanocrystals. High-resolution transmission electron microscopy (HRTEM) showed that the particle size is less than 10 nm in stoichiometric CZTS. The formation of pure kesterite phase was confirmed by X-ray diffraction, HRTEM, Raman spectroscopy, energy dispersive X-ray spectroscopy and UV-visible absorption spectroscopy. (C) 2012 Elsevier B.V. All rights reserved.