Electromodulation of the Negative Differential Resistance in an AlGaAs/GaAs Resonant Tunneling Diode

Abstract

In this work, we investigate the impact of the width of the AlGaAs right barrier and the doping concentration in the contact layers on the negative differential resistance (NDR) and the device performance of a double-barrier AlGaAs/GaAs resonant tunneling diode (RTD). Our simulation is performed using a non-equilibrium Green’s formalism (NEGF). The obtained results show that increasing the width Lb2 of the right barrier, strongly reduces the peak-to-valley current ratio (PVCR. Especially, it reduces from 2.5 for symmetric RTD AlGaAs (5 nm) / GaAs (5 nm) to 1.1 when the right barrier AlGaAs is equal to 8 nm. Our findings show that a specific width of the right barrier Lb2 = 9 nm exists for which the NDR disappears completely. In addition, an increase in the doping concentration in the contact layers is found to reduce the (PVCR) and, consequently, the (NDR). These results open the door for designing resonant tunneling diodes with suitable negative differential resistances. The simulation of the RTD is performed with the use of Nanohub tools which confirms the various results presented in this paper.