Stark-effect scattering in rough quantum wells

A scattering mechanism stemming from the Stark-shift of energy levels by electric fields due to interface roughness in semiconductor quantum wells is identified. This scattering mechanism feeds off interface roughness and electric fields and modifies the well known "sixth-power" law of electron mobility degradation. This work first treats Stark-effect scattering in rough quantum wells as a perturbation for small electric fields and then directly absorbs it into the Hamiltonian for large fields. The major result is the existence of a window of quantum well widths for which the combined roughness scattering is minimum. Carrier scattering and mobility degradation in wide quantum wells are thus expected to be equally severe as in narrow wells due to Stark-effect scattering in electric fields. (C) 2011 American Institute of Physics. [doi:10.1063/1.3607485]