Nearly monodisperse CdS semiconductor nanocrystals have been successfully synthesized by a simple solvothermal synthetic route in the presence of oleic acid and octadecylamine as surfactants, using cheap and low-cost normal inorganic compounds cadmium chloride and sulfur powder as precursors. The size of the nanocrystals was 13 nm. The nanocrystals were analyzed by X-ray diffraction and transmission electron microscopy. Furthermore, the optical properties of as-prepared nanocrystals were characterized by photoluminescence spectra and UV-Vis absorption spectra. The results indicate that the monodisperse nanocrystals exhibit good optical properties. Additionally, the reaction temperature of solvothermal method plays an important role in the synthesis of nanocrystal monodisperse. The possible nanocrystal formation mechanism has been investigated.

Key words: solvothermal, CdS, nanocrystal