Formation and annealing of radiation defects in GaAs doped by various donor impurities

To study an interaction between radiation defects and doping impurities the features of change of electrical properties of the crystals of GaAs (Te) (n0 = 2.4*1017 cm-3), GaAs (Sn) (1.5*1017 cm-3) and nuclear transmutation doped GaAs (1*1017 cm-3) after irradiation by the fast electrons (4 MeV) at T = 300 K and during realisation of the isochronous annealing were studied. A compensation level was determined by the mobility rate at 77 K and was equal to 0.1, 0.2 and 0.4 consequently. The Hall effect and electrical resistance were measured at a constant current in the temperature range 77-300 K. It is confirmed the shallow donor impurities don't participate in a producing of radiation defects at initial stages of electron irradiation at room temperature. However at T>500 K the donor impurities interact with radiation defects, which are mobile at such temperature. An annihilation model of some radiation defects is offered. 6 refs., 2 figs