中文摘要：

采用基于密度泛函理论（DFT）框架下广义梯度近似（GGA）的PBE平面波超软赝势方法。研究了闪锌矿型CdS和Zno1-xSx。（x=O，0．25，0．5。0．75。1）的电子结构和光学特性。计算并分析了闪锌矿型CdS和Zno1-xSx的复介电函数、光电导率、吸收系数和损失函数。研究结果表明。闪锌矿型CdS和Zno1-xSx（x=0。0．25。0．5，0．75,1）均为直接带隙半导体材料。ZnO中一定浓度的硫掺杂，导致带隙宽度变窄。而晶格常数随掺杂基本呈线性变化。就目前制备铜铟镓硒（CIGS）薄膜太阳能电池普遍使用CdS缓冲层而言。Zno1-xSx具有与CdS类似的电子结构，但光学特性上高频特性有明显改善。这些特性对于改善电池吸收层表面性能和光吸收特性、制备高效ClGS薄膜太阳能电池非常有利。

英文摘要：

In this paper, the electronic structure and optical properties of zinc blend-type compounds CdS and Zno1-xSx（x=0, 0.25, 0.5, 0.75, 1） are numerically analyzed by means of the plane wave ultrasoft pseudo-potential method with the generalized gradient approximation （GGA） under the density functional theory （DFT）. The lattice parameters, the band structure, the density of states and the optical conductivity are obtained. The optical properties including the dielectric function, the conductivity, the absorption spectrum and the energy-loss spectrum are discussed. It shows that the zinc blend-type compounds CdS and Zno1-xSx are both direct band gap materials; the crystal constants increase with the quantity of S doping ZnO; the Zno1-xSx has a wider band gap than CdS and can be expected to provide a high quality buffer layer for high efficiency Cu（In1-XGaX）Se2 （CIGSe） solar cells by improving the surface quality of absorption layer and decreasing the absorption loss.