The annealing behavior of cation antisites, and of new defects which had been produced by 30MeV electron irradiation of Fe-doped semi-insulating material, was studied by using photoluminescence, van der Pauw and infra-red absorption methods. In the case of Fe-doped samples, 2 photoluminescence emissions were associated with a double acceptor, InP, which lay at 0.03 and 0.117eV above the valence band. These annihilated in an annealing stage at 300 to 350C. The InP defects in undoped samples were some 100 times smaller than those which were produced in Fe-doped material. In Fe-doped samples, a new emission was also observed near to an emission that was related to the deep InP level. The emission was not observed in undoped material. The new defect was suggested to be a complex one which consisted of an Fe impurity and an irradiation-induced P vacancy. The infra-red absorption near to the absorption edge of Fe-doped material shifted to a higher wavelength with increasing electron dose. The variation in absorption was not observed in undoped InP.

K.Kuriyama, K.Sakai, T.Kato, T.Iijima, M.Okada, K.Yokoyama: Materials Science Forum, 1995, 196-201, 1443-8