Carrier scattering by impurity potentials with spatially variable dielectric functions

Abstract

A spatially dependent dielectric function $\epsilon \mathrm{}\left(r\right)\mathrm{}$ was introduced into the ionized-impurity potential in semiconductors, and the resultant scattering rates and mobilities were calculated. Without donor-acceptor compensation, only for very high doping would there be a marked deviation of the calculated mobility from the Brooks-Herring mobility. For compensated semiconductors, a compensation-ratio-dependent decrease is found in the calculated mobility. This decrease is found to be more pronounced the larger the electron effective mass of the semiconductor is. Available experimental data are discussed as a possible check of the proposed theory, and the need for new experiments is established.