Trends of deep level electron traps in AlxGa1−xAs grown by molecular beam epitaxy

Abstract
Deep level transient spectroscopy is used to study one of the deep electron traps commonly seen in AlxGa1−xAs grown by molecular beam epitaxy (MBE). This trap, having the largest capture cross section of the commonly observed levels in MBE material, is measured in samples with Al composition varying from 8 to 40%. It is shown that the activation energy remains fixed with respect to the valence band, over the composition range studied. The trap is tentatively identified as a group III related vacancy. The effects of varying MBE growth parameters are discussed.