Biomolecule-assisted synthesis of copper indium sulfide microspheres with nanosheets

Copper indium sulfide product was successfully synthesized via a mild solvothermal approach involving CuCl2·2H2O as the copper source, InCl3 as the indium source, l-cysteine as the sulfur source and N,N-dimethylformamide as the reaction medium respectively at 200 °C for 12 h. Morphology, structure, and phase constituents of the as-prepared CuInS2 powders were characterized by XRD, FE-SEM, XPS, and TEM (HRTEM). Results showed that the synthesized powder consists of microspheres made up of nanosheets and the thickness of the CuInS2 nanosheets was found to vary from 50 to 100 nm. A possible formation mechanism was put forward and briefly discussed. The proposed solvothermal method using l-cysteine as the sulfur source offers a potential alternative avenue to prepare other ternary semiconductor nanomaterials.