INTERFACE ROUGHNESS SCATTERING IN A SUPERLATTICE

The authors examine the role of interface roughness (IFR) scattering in electron transport in a GaAs/GaAlAs superlattice, using a simple model. The IFR is assumed to be small, slowly varying and to be characterised by a height and a lateral size. In contrast with previous studies of IFR scattering the authors take the barrier height to be finite. They find that the use of an infinite barrier approximation leads to large errors. They use Fermi's golden rule to calculate scattering rates and the Boltzmann transport equation to calculate IFR scattering-limited mobility in the growth direction at 300 K for a low density non-degenerate electron gas. The authors find that the mobility limited by IFR scattering is up to an order of magnitude less than the predicted LO phonon scattering-limited mobility.