Abstract: In this paper, using deep-level transient speotroacopy (DLTS) and surface photo voltage (SPV), the defects induced by different doses of electron irradiation with 1 MeV of energy in the N-type LPE and VPE-GaAs layers, and their isochronal annealing behavior at temperatures ranging from 400 K to 550 K have been systematically studied. The variations of defect concentration N_T are discussed as the electron radiation dose increases and after isochronal annealing takes place. And it is shown that the main recombination centre level among all the defect levels induced by electron radiation can be identified according to the L²/D-N_T^-1 graph.

Key words: Electron irradiation, Recombination centre, Minority carrier life