Enhancement of multisubband electron mobility in asymmetrically doped coupled double quantum well structure

• Published in: Physica. B, Condensed matter Vol. 476; pp. 91 - 95
• Main Authors: Das, S., Nayak, R.K., Sahu, T., Panda, A.K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2015
• Subjects: Asymmetric quantum wells; Asymmetry; Barriers; Condensed matter; Coupled Quantum Well Structures; Electron mobility; Intersubband scatterings; Joining; Multisubband electron mobility; Scattering; Schroedinger equation; Wave functions; Intersubband scatterings; Coupled Quantum Well Structures; Multisubband electron mobility; Asymmetric quantum wells
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2015.07.014

We study the effect of coupling of subband wave functions on the multisubband electron mobility in a barrier delta doped GaAs/AlxGa1−xAs asymmetric double quantum well structure. We use selfconsistent solution of the coupled Schrödinger equation and Poisson's equation to calculate the subband wave functions and energy levels. The low temperature mobility is considered by using scatterings due to ionized impurities, interface roughness and alloy disorder. We show that variation of the width of the central barrier considerably affect the interplay of different scattering mechanisms on electron mobility through intersubband effects. Under single subband occupancy, the mobility increases with decrease in the barrier width as functions of doping concentration as well as function of well width. However, in case of double subband occupancy, effect of intersubband interaction yields opposite trend, i.e., increase in mobility with increase in barrier width. It is gratifying to show that in case of asymmetric variation of well widths the mobility shows nonmonotonic behavior which varies with change in the width of the central barrier under double subband occupancy.