Study of nonmonotonic electron mobility due to influence of asymmetric structure parameters in pseudomorphic heterojunction field effect transistors

Abstract Nonmonotonic electron mobility is obtained in In x Ga 1-x As/GaAs double quantum well pseudomorphic heterostructure field effect transistor by changing the structure parameters. We show that a rapid drop in mobility occurs at the point of resonance of sub-band states due to asymmetric variation of doping concentrations. The sub-band wave function distributions change significantly near the resonance and influence the sub-band mobilities through the scattering potentials, there by causing the dip in μ . The depth of nonlinearity in μ enhances by increasing the central barrier width and the difference between the well widths. On the other hand, variation of μ as a function of asymmetric change of well widths leads to a hump like raise in μ under unequal doping concentrations. Our results of nonlinear mobility can be utilized in low temperature transistor applications.