A novel aqueous phase synthetic route for CuInSe2 nanocrystals

A novel aqueous phase synthetic route for CuInSe2 nanoparticles is presented. In our synthesis, the Se precursor used was Na2SeSO3 and CuI, while InCl3 were used as precursors for copper and indium, respectively. The reaction was performed in water under basic condition in the presence of thioglycolic acid (TGA). TGA has a crucial effect on the formation of CIS nanocrystals in aqueous media. With less amount of TGA compared to the optimum amount, only amorphous CIS was formed while larger amount caused the formation of Cu2-xSe crystals because TGA had a lower reactivity of In3+ to Se2- ion. The ratio of reagents used optimized the structure, while the composition and properties of the nanomaterials obtained were studied applying various techniques such as XRD, SEM, TEM, TG/DSC, and XPS.