Synthesis and optical properties of ZnS nanostructures

Pure and transition-metal (Cu, Mn, Ag)-doped ZnS nanostructures were synthesized by using a thermal evaporation technique. By monitoring the experimental parameters such as deposition temperature, carrier-gas flux density and deposition time, we showed that ZnS nanostructures with different morphologies could be achieved, namely, nanobelts, nanowires and nanorods. A field emission scanning electron microscopy (FE-SEM) study of the obtained ZnS nanowires reveals that their diameters ranged from 30 to hundreds of nanometers while their lengths ranged up to hundreds of micron. Room-temperature photoluminescence (PL) measurements showed a common peak around 517nm for all ZnS nanowires samples, while impurity-related emission bands were observed in doped ZnS nanowires. This result indicates the important role of dopants in controlling the emission color from ZnS nanostructures.