Fabrication, characterization and optical property of CuI nanospheres

Single-crystal cuprous iodide semiconductor nanospheres were fabricated via a mild low-temperature solution route by using polyvinyl pyrrolidone as capping agent and the mixture of water and polyethylene glycol 400 as solvent. The structure, morphology, and properties of the products were characterized by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermal gravimetry and photoluminescence spectrometry. The results showed that the products were CuI nanospheres of ca. 280–650 nm in diameter and were composed of quasi-trigonal particles of ca. 20–40 nm. The phase transformation temperature and the melting point of the products decreased by ca. 12 and 8 °C compared with the bulk CuI. The possible formation mechanism was discussed on the basis of experimental results.