Ab initio calculation of the growth of Te nanorods and Bi2Te3 nanoplatelets

In this paper the growth mechanism of a Te/Bi$_{2}$Te$_{3}$ novel structure is studied by \textit{ab-initio} calculations. The results show that the growth of Te nanorods is determined by the adsorption energy of Te atoms on different crystalline Te surfaces. The adsorption energy of Te on the Te (001) surface is 3.29 eV, which is about 0.25 eV higher than that of Te on the Te (110). This energy difference makes the preferential growth direction along the $<001>$ direction. In addition, the higher surface energy of Bi$_{2}$Te$_{3}$ (110) and the lattice misfit between crystalline Bi$_{2}$Te$_{3}$ and Te along $<001>$ direction are considered to explain the growth of the Bi$_{2}$Te$_{3}$ nanoplatelets, in which Volmer--Weber model is used. The theoretical results are in agreement with experimental observation.