Tunneling time through heterojunction double barrier diodes

Abstract

The quantum mechanical tunneling time through a heterojunction double barrier diode (DBD) is calculated for all incident electron energies (on-resonance and off-resonance). The well-known result of Eisenbud and Wigner is used, and simple analytical results are obtained. The longest time delay occurs at the on-resonance incident energy due to the electron bouncing back-and-forth in the well region of a DBD. In addition to the exact result for the transmission coefficient and time delay, a Breit-Wigner resonant form is also used to model tunneling amplitude in the neighborhood of a resonance. The tunneling time delay consideration indicates that the ultimate device response of DBDs utilizing GaAs  AlGaAs alloy system is in the sub-picosecond or picosecond regime.