基于密度泛函理论的第一性原理,采用全势线性缀加平面波方法(FPLAPW)和广义梯度近似(GGA)来处理相关能,计算了Cr掺杂SnO2超晶格的电子态密度、能带结构、介电函数、吸收系数、反射率和折射率.研究表明由于Cr的掺入,超晶格SnO2在费米能级附近形成了新的电子占据态,出现了不连续的杂质能带,这是由Cr-3d态和O-2p,Sn-5s态电子所形成.介电谱在0—5.5eV之间时出现了三个新的介电峰,在高能区介电谱主峰位置发生蓝移,峰值强度减小.吸收谱、反射谱和折射谱也出现了与介电谱相应的峰,各谱峰的出现是由Cr的d—d跃迁所引起的.
By the full-potential linearized augmented plane-wave method (FP-LAPW), we investigate the electronic structure, the band structure, the dielectric function, the absorption spectrum, the reflectivity and the refraction of Cr doped SnO2 superlattice. The generalized gradient approximation (GGA) is used for handling correlation energy. Calculation results show that due to the Cr doping, SnO2 superlattice forms new electron occupied state near Fermi energy level and uncentinuous impurity band comes into being, which is contributed by Cr-3d and O-2p, Sn-5s. In dielectric spectrum appear three new dielectric peaks between 0 eV to 5.5 eV. In high-energy area, the position of main peak has a blue-shift and the peak intensity reduces. Absorption spectrum, reflectivity spectrum and refraction spectrum also have peaks corresponding to the dielectric peaks, which are caused by d—d transition of Cr atom.