Interface optical phonon-assisted tunneling in double-barrier structures

The phonon-assisted tunneling current in an asymmetric double-barrier structure is studied theoretically by considering the electron-interface optical-phonon interaction. The numerical results are obtained for the typical AlxGa1-xAs/GaAs/A1(y)Ga(1-y)As structures and a new theoretical understanding about the experimental peaks of phonon-assisted tunneling current is proposed. It is found that only one phonon-assisted tunneling peak appears near the frequency of the well-longitudinal optical-phonon modes for the wider well case, and the contribution from the interface optical-phonon-assisted tunneling on the peak is dominant. The theory can explain the previous experimental results rationally.