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

In this paper the growth mechanism of a Te/Bi_2Te_3 novel structure is studied by 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_2Te_3 (110) and the lattice misfit between crystalline Bi_2Te_3 and Te along <001> direction are considered to explain the growth of the Bi_2Te_3 nanoplatelets, in which Volmer--Weber model is used. The theoretical results are in agreement with experimental observation.