Large-scale synthesis and characterisation of Ag/Bi2Te3 superlattice nanowires via pulse electrodeposition

Ag/Bi2Te3 superlattice nanowire arrays have been fabricated by pulse electrodeposition using porous anodic aluminium oxide as the template at large-scale quantity. The nanowire arrays were characterised by X-ray diffraction, a scanning electron microscope, a transmission electron microscope and high-resolution transmission electron microscopy (HRTEM). The results indicate that the nanowires are composed of the Bi2Te3 rhombohedral lattice phase and the Ag cubic lattice phase with alternately ordered multi-segment characters. The feature of dark segments alternated with bright segments can be easily distinguished because of the obvious heterogeneous contrast. The length of each segment varies from 25 to 45 nm. The HRTEM result shows that the composition of one segment is Ag and the neighbouring segment is Bi2Te3.