Electron irradiated GaSb samples were investigated by positron lifetime spectroscopy(PAS) and the coincidence Doppler broadening(CDB) technique.PAS measurement indicated that there were monovacancy-type defects in undoped GaSb samples
which were identified to be predominantly Ga vacancy(V
Ga
) related defects by combining the CDB measurements.This type defect has lifetime about 284 ps.Electron irradiation could increase its concentration and thus its average lifetime increased from 264 ps(non-irradiation) to 268 ps(irradiated).Positron shallow trapping have been observed and should be due to Ga
Sb
defects after annealing at 500 ℃.Experiments of Zn doped and Te doped GaSb samples proved that V
Ga
284 ps
related defects could be induced by electron irradiation.