INTERNAL-FRICTION IN UNDEFORMED AND DEFORMED GAAS BY THE FORMATION AND RECOVERY OF METASTABLE EL2

The internal friction technique is applied to investigate the transfor mations between the normal and metastable states of EL2-like defects i n undeformed and deformed GaAs. By deformation EL2-like defects are in troduced, which are quenchable by light. A spatial distribution of the transformation rate is found which is discussed in terms of stress va riations throughout the sample. The recovery of metastable EL2 and a metastable EL2-acceptor complex can be observed in undeformed materia l by the emission of carriers but not in deformed material. The latter result is attributed to dislocation levels, which act as traps for th e released carriers.