Mobility modulation in inverted delta doped coupled double quantum well structure

We have studied the modulation of electron mobility mu as a function of the electric field perpendicular to the interface plane F-p in a GaAs/AlGaAs double quantum well structure near the resonance of subband states. The functional dependence of mu on F-p exhibits a minimum near the anticrossing of subband states leading to an oscillatory behavior of mu. We show that the oscillatory enhancement of mu becomes more pronounced with increase in the difference between the doping concentrations in the side barriers. The oscillation of mu also increases by varying the widths of the two wells through shifting of the position of the middle barrier. It is interesting to show that the oscillation of mu is always larger when there is doping in barrier towards the substrate side compared to that of the surface side due to the difference in the influence of the interface roughness scattering potential. Further, broadening of the central barrier width increases the peaks of the oscillation of mu mostly due to the changes in the ionized impurity scattering potential. Our results can be utilized for the performance enhancement of quantum well field effect transistor devices. (C) 2016 Elsevier B.V. All rights reserved.