Electronic structure and optical properties of Cr doped SnO 2 superlattice

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 SnO 2 superlattice. The generalized gradient approximation (GGA) is used for handling correlation energy. Calculation results show that due to the Cr doping, SnO 2 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.