采用基于密度泛函理论的第一性原理计算了CdTe(110)表面的原子和电子性质。结果表明,CdTe(110)理想表面在禁带中出现两个明显的表面态,弛豫后表层Cd原子和Te原子p态电子发生转移,Cd原子趋向于sp2平面杂化构型,Te原子趋向p3杂化的锥形构型。经过表面弛豫大大降低了表面能,增大了表面功函数,表面占据态和表面空态分别被推进价带顶之下和导带底之上,导致弛豫表面没有明显的表面态。
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.