Growth and photoluminescence of zinc blende ZnS nanowires via metalorganic chemical vapor deposition

We developed a metalorganic chemical vapor deposition to synthesize ZnS nanowires with high purity on Au-coated sapphire substrates at low temperatures. The ZnS nanowires have zinc blende structure, and most of them have raw-like surface on one edge, while is smooth on the other. High-resolution transmission electron microscopic investigations show that the nanowires are well crystalline single crystal grown along [1 1 1] and are free of bulk defects. The growth mechanism is confirmed as a typical vapor-liquid-solid process. The photoluminescence spectrum reveals two prominent blue emissions centered at 452.2 and 468.6 nm, respectively. It is found that sulfur vacancies and surface states should be responsible for the two blue emissions, respectively. (C) 2011 Elsevier B.V. All rights reserved.