Facile synthesis of cadmium selenide nanowires and their optical properties

Well crystalline cadmium selenide (CdSe) nanowires were fabricated on the composite layer of gold and carbon coated Si substrates by a facile chemical vapor deposition method. These nanowires are of single-crystalline hexagonal structure and the average length is up to tens of micrometers. The growth process follows a typical vapor–liquid–solid (VLS) mechanism, and the carbon layer can distinctly enhance the VLS process of the CdSe nanowires. The cathodoluminescence (CL) spectrum of an individual nanowire reveals a strong near-band-edge (NBE) emission and relative weak infrared emission centered at 710 and 981 nm, respectively. The defects-related infrared emission is ascribed to the deep defect donors-related energy level induced by a large amount of Se vacancies.