Multiphonon mechanism of the ionization of traps in Al$_2$O$_3$Experiment and numerical simulation

Charge transfer in Al₂O₃ has been investigated experimentally and theoretically. The experimental results are in qualitative agreement with the theory of the multiphonon ionization of deep centers. The thermal (W _T = 1.5 eV) and optical (W _opt = 3.0 eV) energies of the deep centers have been determined. It has been found that the experimental data are unsatisfactorily described by the Pool-Frenkel mechanism, which provides a non-physically small frequency factor and anomalously large effective tunneling mass.