electrical properties of the proton-irradiated semi-insulating GaAs:Cr

The n-p conversion of the conduction type and a decrease in resistivity to 102 Ω cm at 300 K were revealed upon proton irradiation (5 MeV, 300 K, D≈2×1017 cm−2) of semi-insulating GaAs:Cr (ρ≈(3–4)×108 Ω cm). Temperature dependences of ρ for heavily irradiated samples indicate a hopping conduction in the temperature range of 400–120 K, with the transition to the conduction with variable-range hopping at T≤120 K. The effects of electronic switching were found in low-resistivity proton-irradiated GaAs:Cr at about 20 K. The isochronous annealing of radiation defects in the temperature range of 20–750°C was investigated.