Charge transfer in photoexcited Al_xGa_1-xAs/GaAs heterojunctions

Charge transfer in photoexcited AlxGa1-xAs/GaAs heterojunctions is calculated under the assumption that electrons excited into the conduction band of AlxGa1-xAs from donor levels are prevented from recombining with the ionized donors at low temperatures by a barrier of microscopic origin, but are able to maintain quasi-equilibrium with electrons in the GaAs channel. The results are in reasonable agreement with published data and tend to support the assumptions of the model, including the assumption that each donor in AlxGa1-xAs gives rise to a deep level when x > 0.2. © 1986.