Negative differential resistance in planar graphene quantum dot resonant tunneling diodes

Abstract

Negative differential resistance (NDR), an electronic property present in resonant tunneling diodes, enables high performance terahertz frequency oscillators and multi-state logic and memory devices. An important measure of NDR is the peak-to-valley current ratio (PVCR) and this has been extremely lacking in solid-state NDR devices. Here we show how a dimensional mismatch between the quantum dot and the electrodes of a planar graphene Double Barrier Resonant Tunneling Diode (DB-RTD) greatly enhances the PVCR of the device up to a ratio of 103. Our findings suggest a promising future for the application of planar graphene quantum dot devices in next generation electronics.