Designing two-dimensional electron gases in GaAs/InGaAs/AlGaAs, delta-doped AlGaAs/GaAs, and AlGaAs/InGaAs/GaAs heterostructures for single electron transistor application

We have theoretically studied two types of two-dimensional electron gases ( 2DEGs) in GaAs/ InGaAs/AlGaAs and delta -doped-AlGaAs/GaAs heterostructures for single-electron transistor applications by self-consistently solving t he Schrodinger and Poisson equations. Assuming the dominant effect of the i onized impurity scattering in determining the low-held carrier mobility, it has been shown that introducing an InGaAs layer to the conventional GaAs/A lGaAs heterostructure greatly increases the sheet density of the 2DEG and t he corresponding carrier mobility. The delta -doped AlGaAs/GaAs and AlGaAs/ InGaAs/GaAs heterostructures provide us with an even better control of the 2DEG with higher sheet density and carrier mobility. (C) 2001 American Inst itute of Physics.