Green and low-cost synthesis of CIGSe nanoparticles using ethanol as a solvent by a sonochemical method - A new approach

A sonochemical method was utilized to synthesize Cu(InxGa1-x)Se2 (CIGSe) nanoparticles using NaBH4 with ethanol as a solvent. The effect of the ultrasonification time intervals on the synthesis was investigated in the range of 2-5 h, 5 h was found to be the most suitable time to obtain the expected CuIn0.7Ga0.3Se2 compounds. The as-synthesized CIGSe nanoparticles possessed a tetragonal structure with quasi-spherical shape, band gap of ∼1.25 eV, and targeted Cu(InxGa1-x)Se2 composition. A new reaction scheme is proposed to explain the role of NaBH4 in the plausible reaction paths. The non-toxic solvent used in the synthesis with no additional heating makes the developed method cheaper and “greener” than the previously reported methods.