A quantitative study was made of the annealing characteristics of deep-level defects in specimens with B-doped p-type base layers which were introduced by 1MeV electron irradiation. Normal isochronal annealing produced a different overall annealing behavior for defects in type-converted (n-type) heavily (1017/cm2) electron-irradiated samples, to that found for lower doses. Isochronal annealing provided evidence that the minority carrier trap (Ec - 0.18eV) and majority carrier trap (Ec - 0.71eV) which appeared after type-conversion played a predominant role in carrier removal, and were the major defects which were responsible for type-conversion as well as for a severe degradation of space solar cells. This study also indicated why heavy electron irradiation not only changed the structure of a device (p-type to n-type) but also made the defect structure more complex as compared with the simple defect structure of low-dose samples.

Effects of Annealing on Type Converted Si and Space Solar Cells Irradiated with Heavy Fluence 1MeV Electrons A.Khan, M.Yamaguchi, S.J.Taylor, T.Hisamatsu, S.Matsuda: Japanese Journal of Applied Physics - 1, 1999, 38[5A], 2679-85