Ag,Zn掺杂对CdS电子结构和光学性质的影响

运用密度泛函平面波赝势方法和广义梯度近似, 对替代式掺杂Ag和Zn的闪锌矿CdS的超晶胞晶体结构、电子结构和光学性质进行了计算, 分析了其电子态分布与结构的关系,给出了掺杂前后CdS体系的介电函数和复折射率函数. 研究表明,掺有Ag的CdS晶体空穴浓度增大,会明显提高材料的电导率, 而Zn掺杂不改变CdS晶体载流子浓度; Ag, Zn掺杂体系光学带隙均变窄; 通过分析掺杂前后CdS晶体的介电函数和复折射率函数,解释了体系的发光机理. 关键词： 密度泛函理论 Ag,Zn掺杂CdS 电子结构 光学性质

Doped with Ag and Zn effects on electronic structure and optical properties of CdS

The geometry structure, electronic structure and optical properties of zinc bende CdS:M (M = Ag,Zn) were studied systemically using density functional theory based on first-principles ultrasoft pseudopotential method and GGA.The relationship between the distribution of the electronic states and their structures has been analyzed. The dielectric function and the complex refractive index function on doping CdS system have been obtained. The calculation results showed that the hole concentration of Ag-doped CdS is increased, enhanced the conductivity of the material. But the carrier concentration of Al-doped CdS was not changed; the optical band gap were narrowed for Ag-doping, Zn-doping CdS. The mechanism of luminescence has been explained in terms of an analysis of the dielectric function and the complex refractive index function.