Sonochemical synthesis of CuIn0.7Ga0.3Se2 nanoparticles for thin film photo absorber application

CuInGaSe2 (CIGS) has been considered as promising solar absorber material for thin film solar cells leading to efficiencies exceeding 22% on lab scale. CIGS thin film solar cells fabricated from CIGS nanoparticles (NPs) inks by nonvacuum techniques is essential for cost effective cell fabrication process and for upscaling. In this regard, one step sonochemical synthesis of CIGS NPs employing relatively non-toxic precursors of metallic salts and selenourea in an aqueous medium under ambient conditions is being presented. Precursor ratios and sonication time were optimized to realize high-quality chalcopyrite crystal phases of CIGS NPs obtained by sonochemical route. X ray diffraction, UV-vis-NIR, Raman, Energy dispersive spectroscopy and Transmission electron microscopy confirmed the formation of tetragonal chalcopyrite CIGS NPs with a band gap of 1.42 eV and NPs size of about 20 nm.