Synthesis of CuInGaSe2 nanoparticles by low temperature colloidal route

Abstract

CIGS nanoparticles were synthesized by a low temperature colloidal route for the absorber layer of photovoltaic devices. The CIGS nanoparticles were prepared by reacting CuI, InI3, GaI3 in pyridine with Na2Se in methanol at 0°C under inert atmosphere. The reaction products of dark red and yellow colors were turned out to be NaI and CIGS nanoparticles, respectively, by ICP-AES and SEM-EDS analyses. Chalcopyrite structure of the CIGS nanoparticles was confirmed by XRD and TEM diffraction patterns. As compared to the particles from Cu0.9In0.8 Ga0.3Se2 ratio, more uniform and smaller nanoparticles were obtained from Cu1.1In0.68Ga0.23Se1.91 stoichiometric ratio. The CIGS nanoparticles were measured to be in the ranges of 5-20 nm. However, tube like CIGS particles with length of several γn and width in the range of 100-300 nm were obtained from Cu0.9In0.8Ga0.3Se2, and Cu0.9In0.7Ga0.4Se2. The morphological change of the CIGS particles seems to be closely related to the ratio of Cu/(In+Ga).