Solvothermal Synthesis and Characterization of Chalcopyrite CuInSe(2) Nanoparticles

The ternary I-III-VI(2) semiconductor of CuInSe(2) nanoparticles with controllable size was synthesized via a simple solvothermal method by the reaction of elemental selenium powder and CuCl as well as InCl(3) directly in the presence of anhydrous ethylenediamine as solvent. X-ray diffraction patterns and scanning electron microscopy characterization confirmed that CuInSe(2) nanoparticles with high purity were obtained at different temperatures by varying solvothermal time, and the optimal temperature for preparing CuInSe(2) nanoparticles was found to be between 180 and 220 °C. Indium selenide was detected as the intermediate state at the initial stage during the formation of pure ternary compound, and the formation of copper-related binary phase was completely deterred in that the more stable complex [Cu(C(2)H(8)N(2))(2)](+) was produced by the strong N-chelation of ethylenediamine with Cu(+). These CuInSe(2) nanoparticles possess a band gap of 1.05 eV calculated from UV–vis spectrum, and maybe can be applicable to the solar cell devices.