Optical absorption measurements on plastically deformed GaAs show that the total extrinsic absorption increases with deformation, while the quenchable EL2 absorption stays constant. The nonquenchable extrinsic absorption is observed to be proportional to the EPR measured ${\mathrm{As}}_{\mathrm{Ga}}$ containing defects produced during deformation. Since the ${\mathrm{As}}_{\mathrm{Ga}}$-related defects produced by plastic deformation anneal at T∼650 °C, the implication for any correlation between EL2 and ${\mathrm{As}}_{\mathrm{Ga}}$ antisites is that only those ${\mathrm{As}}_{\mathrm{Ga}}$-related EPR centers which are stable up to at least 950 °C can possibly be responsible for the EL2 level.

• Received 12 August 1985

DOI:https://doi.org/10.1103/PhysRevB.33.5880