Au-catalyst growth and photoluminescence of zinc-blende and wurtzite ZnS nanobelts via chemical vapor deposition

Zinc-blende (ZB) and wurtzite (W) ZnS nanobelts have been achieved by rapid chemical vapor deposition at 1050 degrees C, with An as catalyst and graphite as reductant. The size and crystal structure of ZnS nanobelts were influenced by the deposition temperature. In general, the ZnS nanobelts deposited at 600 degrees C were smoother and smaller than those at 800 degrees C. X-ray diffraction spectrum shows the ZnS nanobelts deposited at 600 degrees C were mainly ZB-ZnS, but those at 800 degrees C were only W ZnS. Transmission electron microscopy image and selected-area electron diffraction pattern show three crystal structures of ZnS nanobelts which were deposited at 600 degrees C: ZB ZnS growing along [001], W ZnS along [0-110] and the co-existence of ZB-twins and W ZnS. The PL spectrum of the nanobelts under a He-Cd laser excitation shows a blue peak at 420 nm originating from ZnS self-activated center of ZnS and a green emission at 520 nm from An impurity center. (c) 2006 Elsevier B.V. All rights reserved.