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)3·5H2O 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.

► Te-rich Bi2Te3 nanowire arrays formed in a DMSO solution containing Te+4 and Bi+3.
► Potential pulse plating improves the composition uniformity in a Bi2Te3 nanowire.
► The change of pause times does not affect the preferential orientation of nanowires.
► The electrical resistivity of a Bi2Te3 nanowire deposited from a DMSO solution is high.
► Definite Bi2Te3/Te multilayered nanowire arrays synthesized in a DMSO solution.