Chalcopyrite CuInGaSe2 (CIGS) nanoparticles for solar cell were successfully synthesized by using a relatively simple and convenient elemental solvothermal route. From the reactions of elemental Cu, In, Se and Ga powders in an autoclave with ethylenediamine as a solvent, spherical CIGS nanoparticles with diameter in the range of 30-80 nm were obtained at temperatures in the range of 180-280 degrees C, whereas plate-like particles were obtained at 140 degrees C. The addition of gallium to the elemental solvothermal route for CuInSe2 particles lowered the reaction temperature for the formation of the CIGS nanoparticles, which was studied with the Solution-Liquid-Solid (SLS) mechanism. (c) 2004 Elsevier B.V. All rights reserved.