Numerical approximations to the treatment of interface roughness scattering in resonant tunnelling diodes

Current calculations for a resonant tunnelling diode which include a self-consistent Born treatment of interface roughness combined with full charge self-consistency are presented. Approximate but more computationally tractable solutions which either ignore the scattering-assisted charge or the real part of the self-energy are compared with the full solution. The coherent tunnelling calculation combined with quantum charge self-consistency provides an accurate estimate of the resonant current. To obtain the same accuracy while including interface roughness scattering for our particular device requires a treatment of both the real and the imaginary parts of the self-energy combined with a fully self-consistent treatment of the scattering-assisted charge.