Template-free Synthesis and Transport Properties of Bi2Te3 Ordered Nanowire Arrays via a Physical Vapor Process

Bi2Te3 thin films, composed of ordered nanowire arrays, have been successfully fabricated by a convenient physical vapor deposition method without using any template. The composition and microstructure of these films were determined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). The effects of deposition rate, substrate temperature, and deposition time on morphologies of Bi2Te3 films were investigated. The effects of morphology of film on the electrical conductivity and Seebeck coefficient were also studied. The results show that the nanowire arrays are composed of single-crystalline Bi2Te3 nanowires with diameters of about 18 nm. The nanowires are parallel to each other and uniformly distributed. The film of nanowire arrays shows good transport properties. The growth mechanism of such nanostructure was proposed.