Preparation and characterization of CuInX 2 (X=S, Se, Te) nanoparticles using the liquid polyols

Chalcopyrite-type semiconductors Cu-III-VI2 (III =Al, Ga, In; VI=S, Se, Te) and their solid solutions continue to receive considerable attention due to their potential applications in optoelectronic devices. There has been much interest in the development of synthetic methods to produce chalcopyrite-type compounds. Herein, we developed a facile method to directly produce the CuInS2, CuInSe2, and CuInTe2 nanoparticles in liquid polyols [diethylene glycol (DEG) or tetraethylene glycol (TEG)]. The CuCl (or CuCl2·2H2O), InCl3, S, Se, Te, and NaBH4 were used as raw materials. The CuInS2 and CuInSe2 nanoparticles were synthesized through reduction of raw materials in DEG while CuInTe2 nanoparticles were prepared in TEG. X-ray powder diffraction studies show that these chalcopyrite-type nanoparticles are formed in the body-centered tetragonal structure. In addition, the mean crystallite size of nanoparticles could be controlled between 5 and 40 nm depending on the reaction temperature and reaction times. The synthesized nanopowders were characterized by transmission electron microscopy (TEM), Roman spectroscopy and UV–vis absorption spectroscopy. * This project is financially sponsored by National Science Council (grand no. NSC 96-2112-M-218 -001-MY3).