Electron transport through cubic InGaN/AlGaN resonant tunneling diodes

Abstract

We theoretically study the electron transport through a resonant tunneling diode (RTD) based on strained AlxGa1−xN/In0.1Ga0.9N/AlxGa1−xN quantum wells embedded in relaxed n- Al0.15Ga0.85N/strained In0.1Ga0.9N emitter and collector. The aluminum composition in both injector and collector contacts is taken relatively weak; this does not preclude achieving a wide band offset at the border of the pre-confinement wells. The epilayers are assumed with a cubic crystal structure to reduce spontaneous and piezoelectric polarization effects. The resonant tunneling and the thermally activated transfer through the barriers are the two mechanisms of transport taken into account in the calculations based on the Schrödinger, Poisson and kinetic equations resolved self-consistently. Using the transfer matrix formalism, we have analyzed the influence of the double barrier height on the resonant current. With an Al composition in the barriers varying between 30% and 50%, we have found that resonant tunneling dominates over the transport mediated by the thermally activated charge transfer for low applied voltages. It is also found that the designed n-type InGaN/AlGaN RTD with 30% of Al composition in the barriers is a potential candidate for achieving a resonant tunneling diode.