Chalcopyrite of copper indium gallium selenium (Cu(InxGa1-x)Se-2; CIGS) nanoparticles for solar cell materials have been successfully synthesized by a relatively simple and convenient method, i.e., a modified polyol route. The In/Ga ratio in the CIGS nanocrystals can be controlled by varying the In/Ga ratio in the reaction, and the optical properties of the CIGS nanocrystals correspond to those of the bulk materials. The use of reactants, CuCl, InCl3, GaCl3 and Se powders, in a three-neck flask with tetraethylene glycol as a solvent, spherical CIGS nanoparticles with diameter in the range of 40-100 nm can be obtained at temperatures in the range of 200-280 degrees C. Incorporation of gallium into the CuInSe2 compound requires a much higher reaction temperature for the formation of the CIGS nanoparticles. The characteristics and average sizes of these nanoparticles are analyzed with sophisticated instruments, such as SEM, TEM, EDS, X-ray diffraction pattern, and XRD. (C) 2011 Elsevier B.V. All rights reserved.