CdS nanowires array on Cd foil: synthesis and optical properties

• A uniform and perpendicular-to-substrate CdS nanowires array is synthesized by a simply solvothermal method.
• The Cd foil is used as the precursor of Cd2+ and the substrate.
• The CdS nanowires show the preferred (0 0 2) orientation.
• The narrow full width at half maximum of ~19 nm from the band gap emission indicates that the size contribution of nc-CdS is smaller.

A uniform CdS nanowires array is grown on the Cd foil through a simply solvothermal method using the Cd foil as the precursor of Cd2+ and the substrate. The CdS nanowires are perpendicular to the Cd foil and show the preferred (0 0 2) orientation, which have the diameters of ~20–40 nm and lengths of ~10–13 μm. The optical band gap of ~2.46 eV (~505 nm) for CdS nanowires array is obtained by the Kubelka-Munk method. The green and red emissions under the excitation of 420 nm are ascribed to the band gap emission and the transition from the sulfur vacancies to the valence band of CdS nanowire, respectively. The well-aligned CdS nanowires array could be considered to be an excellent candidate for optoelectronic application.