Solvent solution-dependent properties of nonstoichiometric cubic Cu2ZnSnS4 nanoparticles

Cu2ZnSnS4 (CZTS) quaternary nanocrystals are synthesized by solvothermal synthesis using the various solvents of polyvinylpyrrolidone (CZTS-PVP), ethylene glycol (CZTS-EGL), oleylamine (CZTS-OLA) and octadecene (CZTS-ODE). The X-ray diffraction patterns of the synthesized compounds show preferred orientations of the (1 1 2), (2 0 0), (2 2 0), (3 1 2) and (3 3 2) planes, confirming the kesterite structure of CZTS. The ultraviolet–visible absorption spectra confirm the existence of a direct band gap of about 1.47 eV using the CZTS-OLA sample. A solar cell device with CZTS-OLA as an absorber layer exhibits the highest efficiency of 2.5%.