Magnetic studies of persistent photoconductivity inn-AlxGa1−xAs

Low-temperature magnetic susceptibility measurements were made during illumination of n-${\mathrm{Al}}_2$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As with DX centers to investigate the microscopic origin of persistent photoconductivity. Experiments using a dc SQUID magneto-optic microsusceptometer revealed the change of electronic susceptibility as a function of illumination time and temperature. The results indicate that the DX center is a paramagnetic donor with one unpaired electron.