Characterization of the properties of high-energy electron irradiated Al-doped ZnO thin films prepared by rf magnetron sputtering using Ar plasma

In this study we explored the electrical, optical, and structural properties of Al-doped ZnO (AZO) films prepared with radio frequency magnetron sputtering using argon plasma condition after they were treated by high-energy electron beam irradiation (HEEBI) in air at room temperature. Hall and photoluminescence (PL) measurements revealed that the n-type conductivity was preserved in HEEBI treated films. Hall results also indicated that the AZO films treated by HEEBI with a high fluence of 1016 electrons/cm2 have around three times higher mobility, seven times lower electron concentration, and three times higher resistivity than those of the untreated films. PL and X-ray photoelectron spectroscopy showed that the acceptor-like defects, such as zinc vacancies and oxygen interstitials, increased in the HEEBI-treated films with a high fluence, resulting in the decrease in electron concentration of the films. It was found from scanning electron microscope analysis that a larger grain size was observed in HEEBI treated AZO films with a higher fluence, which is related to rougher surface morphologies in HEEBI treated films with a higher fluence, as confirmed by atomic force microscope. We believe that our results will contribute to develop high quality AZO based materials and devices for space application.

► Properties of AZO films after high-energy electron beam irradiation (HEEBI).
► HEEBI-treated films have higher mobility and lower electron concentrations.
► Zinc vacancies and oxygen interstitials increase in HEEBI-treated films.
► A larger grain size is observed in HEEBI-treated films with a higher fluence.
► Results are useful to develop high quality AZO based devices for space application.