Weuse resonant photoelectron spectroscopy at the Zn 2p, Ga 2p, In 3d, andO1s absorption edges to report on the electronic properties of indium-gallium-zinc-oxide thin films.Wealso compare the data with the respective data of the corresponding single crystals In2O3, Ga2O3, and ZnO.Wefocus on the elemental composition and, in particular, find no evidence for oxygen deficiency. The In, Ga, and Zn absorption data at resonance can be used to analyze the conduction band states in detail.We deduce that a configuration interaction between d10s and d9s1states is of importance. Weprovided a novel mechanism in which configuration interaction induced gap states create both, extended unoccupied states around EF as well as localized occupied states within the gap.
- In-gap defect states
- Resonant photoelectron spectroscopy
- Transparent conducting oxides