Electrical and Optical Characterization of n-GaN by High Energy Electron Irradiation

The effect of high energy electron irradiation on the electrical and optical properties of n-GaN is studied. Hall and photoluminescence measurements are carried out on the samples irradiated with different doses. The results obtained from Hall measurements show that electron concentration and mobility are proportional to electron irradiation doses. The PL results show that the near-band-edge intensity and yellow luminescence intensity decrease continually with the increasing electron irradiation. However, it is found that the ratio of the yellow luminescence intensity to the near-band-edge intensity increases with the increasing of electron irradiation dose. To interpret this phenomenon, we propose two theoretical models based on the charge transport mechanism and rate equations, respectively, and they are in good agreement with the experimental observations.