Synthesis, Characterization and Growth Mechanism of Bi2Te3 and Te Nanostructures by Vapor-Phase Deposition

Few-layer bismuth telluride nanoplates exhibiting a variety of morphologies with triangular, truncated triangular, hexagonal and circular shapes, have been prepared by vapor phase deposition method in Ar atmosphere under 33 Torr. The influence of growth time, growth pressure and the placement mode of substrates on the formation of bismuth telluride nanostructures have been systemically investigated. Tellurium nanostructures have also been prepared without the aid of surfactants and catalysts, providing an efficient route for the preparation of high-quality tellurium nanostructures. The structure and morphology of Bi2Te3 nanoplates as well as tellurium nanostructures have been investigated by atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy equipped with an energy-dispersive X-ray spectrometer. X-ray diffraction using the Cu K alpha radiation has also been carried out to characterize the crystal structure of the as-synthesized samples. Based on the experimental results, a possible growth mechanism of Bi2Te3 nanoplates and tellurium nanostructures has been proposed.