Electrons drift velocity overshot in heterostructures with double-sided donor-acceptor doping and digital barriers

The nonlocal dynamics of electrons in pseudomorphic AlGaAs/GaAs/InGaAs heterostructures with double-sided donor-acceptor doping of AlGaAs barriers and additional digital potential barriers of short-period AlAs/GaAs superlattices around the doped regions has been theoretically studied. For the studied heterostructures, the introduction of digital barriers significantly, by 30–40%, increases the electrons drift velocity overshot when they enter the region of a strong field. The effect of localization of hot electrons on the states in AlAs/GaAs superlattices along the edges of the InGaAs quantum well is revealed. It is shown that taking this effect into account significantly increases the electrons drift velocity overshot, bringing it closer to the maximum theoretical limit for the model used – the drift velocity overshot in the undoped InGaAs bulk material.