Cu2ZnSnS4/Cu2ZnSnSe4电子结构与光学特性的第一性原理计算

摘要

The electronic structure and optical properties of Cu2ZnSnS4(CZTS) and Cu2ZnSnSe4(CZTSe) were computed by means of plane wave ultrasoft pseudo-potential method with generalized gradient approximation (GGA) under the density functional theory (DFT). The density of states, adsorption coefficient, dielectric function, refractive index, reflectivity, conductivity and loss function were also calculated and compared. The results show that both the kesterite CZTS and the kesterite CZTSe are direct band gap semiconductors. The density of states and optical characteristic curves of CZTS and CZTSe are very similar. But all optical characteristic curves of CZTS slightly shift to high energy compared with that of CZTSe from its wider band gap.%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,计算Cu2ZnSnS4(CZTS)和Cu2ZnSnSe4(CZTSe)的电子结构和光学特性.计算并系统对比分析CZTS和CZTSe的态密度、吸收系数、复介电函数、复折射率、反射率、复电导率和能量损失函数随光子能量的变化关系.结果表明,锌黄锡矿型CZTS和CZTSe都是直接带隙半导体材料.CZTS和CZTSe的态密度和光学特性的曲线非常相似,但CZTS 的禁带宽度比CZTSe的偏大,导致CZTS的各个光学特性曲线相对于CZTSe的略微向高能方向移动.