Interface roughness effects in resonant tunneling structures

We examine the effect of interface roughness on resonant tunneling in double barrier structures using an exactly solvable real-space three-dimensional supercell model. We find that scattering of off-resonance states into on-resonance states provides the dominant contribution to interface roughness assisted tunneling. Our analysis of the sensitivity of scattering strength to interface layer configurations reveals preferential scattering into k∥≊2π/λ states, where λ is the island size. We attribute the broadening and shifting of transmission resonances to lateral localization of wave functions, which we demonstrate directly. We also show that the degree of localization increases with island size.