Electronic structures and stability of Ni/Bi2Te3and Co/Bi2Te3interfaces

We investigate the electronic structures and stability for Ni/Bi2Te3, NiTe/Bi2Te3, Co/Bi2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable.