The influence of dopants in ZnO films on defects was investigated by slow

positron annihilation technique. The results showed S that parameters meet SAl >

Sun > SAg for Al-doped ZnO films, undoped and Ag-doped ZnO films. Zinc

vacancies were found in all ZnO films with different dopants. According to S

parameter and the same defect type, it can be induced that the zinc vacancy

concentration was the highest in the Al-doped ZnO film, and it was the least in the

Ag-doped ZnO film. When Al atoms were doped in the ZnO films grown on

silicon substrates, Zn vacancies increase as compared to the undoped and Agdoped

ZnO films. The dopant concentration could determine the position of Fermi

level in materials, while defect formation energy of zinc vacancy strongly depends

on the position of Fermi level, so its concentration varies with dopant element and

dopant concentration.

Influence of Dopants in ZnO Films on Defects. C.X.Peng, H.M.Weng, Y.Zhang,

X.P.Ma, B.J.Ye: Chinese Physics Letters, 2008, 25[12], 4442-5