Quaternary Cu2ZnSnSe4 particles, useful for low cost solar cell synthesis, were successfully prepared using sonochemistry assisted solid state synthesis method. The pathways of the reactions during the synthesis as a function of the annealing temperature were studied by X-ray diffraction and energy dispersive X-ray spectroscopy (EDS) with the identification of the intermediate binary phases (Cu-Se, Zn-Se, Sn-Se), ternary phases (Cu-Sn-Se, Cu-Zn-Se) and the eventual formation of the quaternary phase Cu2ZnSnSe4. The obtained particles were characterized by X-ray diffraction (XRD). Only the quaternary particles were analyzed by Ultraviolet visible (UV-Vis) optical absorption spectroscopy. The results showed that the annealing temperature of 450 degrees C is optimal for the formation of the pure quaternary phase. However, the temperature range within which pure Cu2ZnSnSe4 could be obtained was very narrow and Cu2ZnSnSe4 decomposes to various binary and ternary phases as the temperature is increased above the stability range. UV-Vis absorption spectroscopy illustrated that the particles had high absorption of visible light and had a direct band gap around 1.2 eV. These findings demonstrated a low-cost and environmentally friendly method to synthesize (LISe particles. (C) 2016 Elsevier B.V. All rights reserved.295 202208Deanship of Scientific Research at King Saud University [RGP-VPP-283]