Carrier heating and electron-phonon energy exchange effects on nonlinear transport phenomena in semiconductor films

Abstract

Theory of nonlinear size effects is developed in semiconductor films in the presence of an external dc electric field. The electron and phonon temperatures are calculated self-consistently with the electron-phonon energy interaction taken into account and its influence on the electron current density is considered. The temperature distributions are calculated using appropriate boundary conditions at the surfaces of the semiconductor film. It is shown that the electron and phonon temperatures depend on the electron-phonon coupling factor and the film thickness. Because the electrical conductivity is a function of the electron and phonon temperature distributions, the electron current density in the semiconductor film becomes nonlinear as a function of the heating electric field. We discuss the nonlinear effects for different special cases.