Cathodoluminescence studies of the electron injection-induced effects in GaN

Local irradiation of p-type GaN with the electron beam of a scanning electron microscope resulted in up to a threefold decrease of the peak cathodoluminescence intensity at similar to379 nm, as was observed in the variable temperature measurements. The cathodoluminescence results are consistent with an increase of the minority carrier diffusion length in the material, as is evident from the electron-beam-induced current measurements. The activation energy for the electron injection effect, estimated from the temperature-dependent cathodoluminescence, is in agreement with the thermal ionization energy of the Mg-acceptor in GaN