Pulsed electrodeposition of single-crystalline Bi₂Te₃nanowire arrays

Thermoelectric material Bi2Te3 nanowire arrays have been successfully prepared by pulsed electrochemical deposition into the nanochannels of porous anodic alumina membranes. X-ray diffraction analyses show that the as-synthesized nanowires have a highly preferential orientation. Scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy observations indicate that the high-filling-rate and uniform Bi2Te3 nanowires are single crystalline. Energy dispersive spectrometer analyses indicate that the compositions of the nanowires can be controlled by changing the potentials and the solution concentrations. The electrical resistance measurements indicate that the resistances increase with decreasing temperature and show a typical semiconductor characteristic. The growth mechanism is discussed together with the electrochemical deposition process studies.