Electron trapping by metastable effective-mass states of DX donors in indirect-band-gap AlxGa1−xAs:Te

Abstract

Electron trapping by metastable effective-mass states of Te donors bound to the X minimum of the conduction band is reported. Their identification is based upon the analysis of a photoinduced metastable infrared absorption and thermally activated persistent photoconductivity in indirect-band-gap ${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As. Analysis of Hall-effect measurements within a two-level donor model supports the hypothesis of a bistable character of DX-type donors.