Fabrication and Growth Mechanism of Selenium and Tellurium Nanobelts through a Vacuum Vapor Deposition Route

High-quality ultrawide Se and Te nanobelts have been prepared through thermal evaporation and deposition of Se and Te bulk powder in a vacuum system. The products were characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HRTEM). Different Se (Te) nanostructure intermediates have been observed in the preparation process through time-dependent experiments. On the basis of the experimental data, the formation of Se and Te nanobelts is believed to follow a vapor−solid mechanism mediated by agglomeration. Furthermore, it is demonstrated that, when subject to electron beams, the Te nanobelts evolve to helical ones.