Effect of in situ annealing on the structural properties of Bi2Te3 films grown on (0 0 0 1) sapphire

Investigation on annealing of Bi2Te3 layers grown on (0 0 0 1) sapphire substrates were carried out. An impressive restructuring process of the Bi2Te3 films (∼50-nm thickness) was observed in-situ during the annealing process. Starting with very rough and rotated polycrystalline Bi2Te3, by the annealing, there was a transformation from the polycrystalline structures to a hexagonal structure and also a significant surface flattening throughout...