The electrical activities of slip dislocations and Frank-type partial dislocations were investigated by using the temperature-dependent electron beam-induced current technique. It was found that both types of dislocation were recombination-active only at temperatures below about 200K, and were inactive at higher temperatures if they were free of decoration by metallic impurities. From the temperature dependence of the electron beam-induced current contrast, the energy levels of recombination centers on the dislocations were deduced to be lower than 0.1eV. They were not associated with any deep levels. The debris of defects which were generated by moving dislocations had deep levels that were some 0.3 to 0.4eV from the band edge; even if there was no decoration with metals. Both slip dislocations and Frank partials became recombination-active at high temperatures when they gettered metallic impurities. The characteristics of the impurity gettering by dislocations depended upon both the impurity species and upon the cooling rate of the crystal after contamination.

S.Kusanagi, T.Sekiguchi, B.Shen, K.Sumino: Materials Science and Technology, 1995, 11[7], 685-90