Resonant tunneling structures with local potential perturbations

Abstract

Self-consistent Schrödinger–Poisson model has been used to handle band-bending effects in resonant tunneling heterostructures with local potential perturbations. Simulation results are presented for a high-quality In0.1Ga0.9As/AlAs/GaAs double-barrier heterostructure in a triple well configuration which we also fabricated and tested. The samples exhibit state-of-the-art conduction characteristics for this material system with a peak-to-valley current ratio as high as 7:1 and a peak current density of 50 kA cm−2. These conduction characteristics are analyzed in terms of tunneling transitions between highly coupled quantum wells by calculating numerically the change in the local density of states due to a bias. Also, we discuss the validity of the Thomas–Fermi screening model which leads to unphysical jumps in the carrier density at heterointerfaces.