The local structure and charge transfer properties of Co-doped ZnO thin films
Co掺杂ZnO薄膜的局域结构和电荷转移特性研究

Zn0.95Co0.05O and Zn0.94Co0.05Al0.01O films were prepared by inductively coupled plasma enhanced physical vapor deposition with magnetic confinement system under different oxygen partial pressure. The local structure and charge transfer properties were investigated by X-ray absorption fine structure and resonant inelastic scattering spectroscopy at O-K, Co-K and Co-L edges. The Co K-edge and L-edge X-ray absorption fine structure revealed that Co2+ ions substituted for tetrahedrally coordinated Zn2+ ions without changing the wurtzite structure. The main defects were oxygen vacancies when the films were deposited under very low oxygen partial pressure. The resonant inelastic scattering spectroscopy indicated that the charge transfer between Co-3d and the electrons in Zn0.94Co0.05Al0.01O films was much stronger than that in Zn0.95Co0.05O. The oxygen partial pressure had an important effect in the charge transfer of Co-doped ZnO films.