TIME-DEPENDENT ELECTRICAL-PROPERTIES OF GAAS DOPED WITH RADIOACTIVE ISOTOPES GA-67 AND AS-71

The results of Hall effect and resistivity measurements on p-GaAs impl anted with Ga-67 (-->Zn-67) and semiinsulating GaAs implanted with As- 71(-->Ge-71-->Ga-71) are presented. In either case, time dependent cha nges of the carrier concentration and resistivity according to the hal f-life of the involved probe atoms could be observed. In the case of G a-67, transmutation from the electrically neutral Ga to the single acc eptor Zn-Ga occurs, For As-71 a transformation into the single accepto r Ge-As is observed. However, the finally resulting Ga-As does not act as a double acceptor, but seems to have a compensating effect.