High-energy Electron Beam Irradiation of Al-doped ZnO Thin Films Deposited at Room Temperature

In this research, we demonstrated the effects of high-energy electron beam irradiation (HEEBI) on the optical and structural properties of Al-doped ZnO (AZO) films grown on transparent corning glass substrates at room temperature (RT) by using a. radio-frequency magnetron sputtering technique. The AZO thin films were treated with HEEBI in air at RT at an electron beam energy of 0.8 MeV and doses of 1 x 10(14) - 1 x 10(16) electrons/cm(2). The photoluminescence (PL) measurements revealed that the dominant peak at 2.77 eV was a blue emission originating from donor-like defects, oxygen vacancies (V(o)), suggesting that the n-type conductivity was preserved in HEEBI-treated films. On the basis of PL, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy results, we suggest that the density of V(o) donor defects is decreased due to in-diffusion of oxygen from the ambient into the films after HEEBI treatment at low doses up to 10(15) electrons/cm(2) while the opposite phenomenon can occur with further increase in the dose. We also found from the XRD analysis that the worse crystallinity with a smaller grain size was observed in HEEBI-treated AZO films at a higher close, corresponding to a higher oxygen fraction in the films. We believe that our results will contribute to developing high-quality AZO-based materials and devices for space applications.