Electrical characterization of electron and proton-induced defects in p+n GaAs photodiodes: EBIC study

Electrical changes in p⁺n GaAs photodiodes are monitored using illuminated current-voltage, quantum efficiency and electron beam induced current measurements after irradiation with 1 and 5 MeV electrons and 2 and 225 MeV protons. Electron beam induced micrographs have revealed the presence of localized defects or active recombination centers after irradiation with protons that are not observed after irradiation with electrons. Moreover, the 225 MeV protons clearly produce defects that are more electrically active compared with those produced by 2 MeV protons, but the implications deduced from the images can be deceiving when compared with the photovoltaic response of the photodiode.