First-principles study of the electronic structures and optical properties of C-F-Be doped wurtzite ZnO

摘要

The electronic structure and optical properties of pure, C-doped, C - F codoped and C - F - Be cluster-doped ZnO with a wurtzite structure were calculated by using the density functional theory with the plane-wave ultrasoft pseudopotentials method. The results indicate that p-type ZnO can be obtained by C incorporation, and the energy level of C _O above the valence band maximum is 0.36 eV. The ionization energy of the complex Zn _(16)O _(14)CF and Zn _(15)BeO _(14)CF can be reduced to 0.23 and 0.21 eV, individually. These results suggest that the defect complex of Zn _(15)BeO _(14)CF is a better candidate for p-type ZnO. To make the optical properties clear, we investigated the imaginary part of the complex dielectric function of undoped and C - F - Be doped ZnO. We found that there is strong absorption in the energy region lower than 2.7 eV for the C - F - Be doped system compared to pure ZnO.