采用基于密度泛函理论(DFT)第一性原理的平面波超软赝势方法,对空位缺陷体系的几何结构进行优化计算,发现空位引起周围原子的弛豫,晶格结构发生畸变。在此基础上研究了空位缺陷对闪锌矿结构CdS体系电子结构(能带结构、电子态密度)的影响,结果表明,S空位使得能带变窄,而Cd空位使带隙变宽,但二者仍为直接带隙半导体。对光学性质的研究发现,由于空位的介入使其邻近原子电子结构发生变化,使得空位缺陷体系光学性质的变化主要集中在低能量区。 The plane wave super soft pseudopotential method based on the first principle of density functional theory (DFT) was used to optimize the geometrical structure of the vacancy defect system. It was found that the vacancy caused the relaxation of the surrounding atoms and the distortion of the lattice structure. The effects of vacancy defects on the electronic structure (band structure and electronic density of states) of CdS system in sphalerite were studied. The results show that the S band vacancy makes the band narrow and the Cd vacancy widens the band gap, Both are still direct bandgap semiconductors. The study of optical properties shows that the electronic structure of neighboring atoms changes due to the vacancy insertion, so that the optical properties of vacancy defects are mainly concentrated in the low energy region.