Template growth of photoconductive metal-CdSe-metal nanowires

Metal-CdSe-metal (metal = An, Ni) nanowires were grown by electrochemical replication of porous aluminum oxide and polycarbonate track etch membranes with pore diameters of 350 and 70 nm, respectively. The lengths of the individual segments of the nanowires were controlled by varying the amount of charge that was passed. The composition of the CdSe segments was characterized by energy-dispersive X-ray spectroscopy. A 1: 1 ratio could be obtained, and Cd- and Se-rich stoichiometries were also made by adjusting the concentrations of Cd4+ and SeO2 in the aqueous plating solutions. X-ray powder diffraction showed the presence of both zinc blende and wurzite phases, and grain sizes on the order of 10 nm were observed by TEM. The nanowires were resistive in the dark but showed pronounced visible light photoconductivity.