DEGRADATION OF MOBILITY IN NEUTRON-IRRADIATED GAAS BY THE INCREASED SCATTERING FROM MULTIPLY CHARGED IONIZED DEFECTS

Mobility changes were measured at temperatures from 15 to 305 K in n-G aAs van der Pauw samples irradiated by fast reactor neutrons. The inve rse mobility values, obtained from the variable temperature Hall measu rements were fitted using the relation mu-1 = AT-3/2 + BT3/2. The inve rse mobility was found to increase as a result of neutron irradiations over the whole range of temperature; the increase is attributed to th e increased scattering from neutron induced charged defects. The value s of A found by the least square fitting were used to estimate the inc reased scattering effect from neutron-induced ionized defects after ea ch step of irradiation. It is concluded that in order to explain the e xperimental results presented here, the creation of multiply charged d efects must be considered.