Preparation and characterisation of single-crystalline structure Sb/Bi2Te3 superlattice nanowires.

High figures of merit is important and necessary for thermoelectric materials in a particular engineering application of thermoelectric generation. Crystalline is an important factor for the high figures of merit of thermoelectric materials. Single-crystalline structure Sb/Bi₂Te₃ supperlattice nanowires (SLNWs) were synthesised in large quantity by pulsed electrodeposition technology using porous anodic alumina oxide as a template. The X-ray diffraction result indicates that the as-prepared compound consists of rhombohedral phase Bi₂Te₃ and monoclinic phase Sb. Transmission electron microscope images demonstrate that the segments of SLNWs are built by Bi₂Te₃ and Sb alternately and exhibit the distinguished interface between two segments. The average diameter and length of each segment are about 80 and 90 nm, respectively. The composition of neighbouring segments was investigated by selected area electron diffraction (SAED), further verifying that the neighbouring segments of SLNWs are comprised of Bi₂Te₃ and Sb. Meanwhile, the spot pattern of SAED indicates these segments are crystallised well. [ABSTRACT FROM AUTHOR]