First-principles study on the atomic and electronic structure of CdTe(110) surface

The atomic and electronic structure of CdTe(110) surface were calculated using first principle method based on the density functional theory. The results show that there are two distinct surface states in the band gap of perfect Cd(110) surface. However, p electron has been transferred between Cd and Te atom due to relaxation. Furthermore, the hybridization of the surface bonds makes Cd atoms tend to form a planar sp² like configuration, while Te atoms tend to form p³ like pyramidal configuration. Surface energy has been greatly decreased after surface relaxation, and the occupied surface state and unoccupied surface state are pushed into the valence band and the conduction band, respectively, which lead to unobvious surface states in the band gap.