Field effect on the deep levels and DX centers in AlxGa1−xAs/GaAs and InxGa1−xAs/GaAs

Abstract

Field effect studies have been performed on the deep levels in molecular beam epitaxially grown AlxGa1−xAs (with x=0.385) and InxGa1−xAs (with x=0.1) on n+‐GaAs. We have measured the isothermal and isofield capacitance transients for the major energy levels with the applied electric field [here, field means normalized field, F(norm)=F(appl)×10−5] in the range −0.5 to −5 V/cm. The results of our investigation suggest that the applied field has a distinct effect on thermal emission rate, capture cross section and activation energy. In particular, the Arrhenius plots showed a nonlinear behavior that could be associated with electron–phonon interactions. Furthermore, the activation energy versus field plots indicate a linear behavior, illustrating a complex nature of the deep levels some of which, E1 in AlxGa1−xAs and E3 in InxGa1−xAs, can be characterized as DX centers.