Morphological evolution and structural characterization of bismuth telluride (Bi₂Te₃) nanostructures

Atomically thin two-dimensional (2D) nanomaterials with a layered structure, such as graphene and hexagonal boron nitride (h-BN), have been attracting a large amount of attention due to their unique properties and fascinating application in several devices for energy harvesting. Recently, single and few-layer Bi₂Te₃ 2D nanosheets have attracted great attention. In this paper, the morphological evolution of Bi ₂Te₃ 2D nanosheets to nanotubes, which were fabricated by bottom-up assembly at low temperature by a controlled wet-chemical growth mechanism, is reported. The products are ultrathin nanosheets with thicknesses down to a few quintuple layers, and single, double and multiwall nanotubes with lengths of up to 2 m. As a new member, Bi₂Te₃ nanotubes have extremely large surface-to-volume ratios and can be electrically gated more efficiently than the bulk form to enhance surface state effects potentially in transport measurements. The method presented herein allows the mass production of identical tubes that can be easily integrated into device structures for futuristic applications.