CuIn_(1-x)Ga_xSe_2/CuIn_(1-x)Al_xSe_2电子结构与光学特性的第一性原理计算

First-Principles Calculation of Electronic Structure and Optical Properties of CuInGaSe_2/CuInAlSe_2

采用基于密度泛函理论(DFT)框架下广义梯度近似的PBE平面波超软赝势方法计算了CuIn1-xGaxSe2(CIGS)和CuIn1-xAlxSe2(CIAS)的电子结构及光学性质.计算结果表明黄铜矿型CIGS和CIAS都是直接带隙半导体材料,禁带宽度分别为1.34 eV,1.50 eV.计算并对比分析了CIGS和CIAS的态密度,吸收系数,反射率,复介电函数和折射指数随光子能量的变化关系.结果表明CIAS的禁带宽度偏大,导致了它的吸收光谱和复介电函数虚部相对于CIGS发生了蓝移,并且反射率较低.

It presents the structural and electronic characterization of CuInGaSe2(CIGS) and CuInAlSe2(CIAS).The fully-relaxed calculations have been made using the density functional theory,and structure constant matches the experimental values.The density of states,adsorption constant,reflectivity,dielectric constant and refractive index are also calculated.The results show that the chalcopyrite CIGS and CIAS are direct band gap semiconductors with band gaps 1.34 eV,1.50 eV respectively.Comparatively,CIAS have higher adsorption and dielectric values with lower reflectivity at high photon energies,which is promising for high efficiency solar cells.