Pulsed electrodeposition of Bi2Te3 and Bi2Te3/Te nanowire arrays from a DMSO solution

Dense, continuous and polycrystalline bismuth telluride (Bi2Te3) nanowire arrays have been deposited from a DMSO solution containing Bi(NO3)(3)center dot 5H(2)O and TeCl4 in porous alumina templates by a pulse electrochemical method. The composition of the nanowire is dependent on the applied potential, and the composition distribution along a single nanowire becomes more uniform as the potential-off time becomes longer. The Bi2Te3 nanowire arrays have a highly preferential orientation along the [1 1 0] direction. Bi2Te3/Te multilayered nanowire arrays have also been deposited from the same DMSO solution. A clear interface between segments of different composition can be distinguished by TEM analysis. The elemental analysis shows the atomic percentage of Te in Te segments to be more than 95 atom%. Bi-rich regions were obtained in the Bi2Te3 segments. (C) 2011 Elsevier Ltd. All rights reserved.