Effect of group V/III flux ratio on deep electron traps in Al<i>x</i>Ga1−<i>x</i>As (<i>x</i>=0.7) grown by molecular beam epitaxy

Abstract

The effect of group V/III flux ratio γ on deep electron traps in AlxGa1−xAs (x=0.7) grown by molecular beam epitaxy at 720 °C has been studied by deep level transient spectroscopy. The photoluminescence characteristics of a GaAs single quantum well sandwiched by Al0.7Ga0.3As are determined by the electron traps denoted as E4–E6(E6′) in Al0.7Ga0.3As with the activation energies of 0.77 eV (E4), 0.72 eV (E5), 0.90 eV (E6), and 1.00 eV (E6′). The concentrations of these traps are minimized to the order of 1013 cm−3 at γ∼2 in spite of high Al content.