Electron mobility limited by ionized impurity scattering with nonlinear screening in semiconductors

Abstract

Electron mobility in GaAs due to ionized impurity scattering is calculated by considering nonlinear screening charge. The calculated values are larger than those obtained with the conventional linearized screening charge. The discrepancy is most important at intermediate carrier densities and may be as large as a factor of 1.8 at 77 K for a carrier concentration of a few times ${10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The Hall-to-drift mobility ratios are, however, not much altered when nonlinear screening is included. Incorporation of nonlinear screening is shown to enhance the disparity between the theoretical and the experimental mobilities at 77 K.