Minority carrier diffusion length and lifetime in p-Zn 0.9 Mg 0.1 O doped with phosphorus were obtained from local electron beam irradiation measurements. The irradiation resulted in an increase of up to 25% in minority electron diffusion length from the initial value of ϳ2.12 m and in a simultaneous decrease of the peak near-bandedge cathodoluminescence intensity. The observed phenomena are attributed to charging of phosphorus-related deep acceptor level(s), which is consistent with the activation energy of 256± 20 meV found for the effect of electron injection in Zn 0.9 Mg 0.1 O.

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 ∼379 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.

Electron injection into Mn-doped GaN resulted in pronounced changes in the minority carrier diffusion length and cathodoluminescence. In particular, multiple-fold decrease of the band-to-band cathodoluminescence intensity was observed in the temperature between −50 and 80°C. This decrease was accompanied by an increase of the minority carrier diffusion length in the material, measured by electron-beam-induced current. Temperature-dependent cathodoluminescence measurements revealed a recovery of the cathodoluminescence intensity with an activation energy of 360meV.

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