Models of resonant-tunneling diodes based on the envelope-function approximation often give unsatisfactory results. In order to address some of the shortcomings of these models, we employ a tight-binding model that allows more careful treatment of heterointerfaces than is possible in the envelope-function approach. We use transfer matrices to carry out the calculation and present an improved method that allows us to transfer across larger device dimensions (>1000 Å), thereby permitting us to include space-charge regions in the model. We compare results obtained with the tight-binding and envelope-function approximations.

• Received 17 September 1990

DOI:https://doi.org/10.1103/PhysRevB.43.4777