A computational study on the device performance of Graphene Nanoribbon resonant tunneling diodes

Abstract

Device performance of semiconducting graphene nanoribbon resonant tunneling diodes (GNR RTDs) with different shapes and dimensions was investigated using the real space, π-orbital tight-binding approach embedded in non-equilibrium Green's function formalism. The robustness of the device operating mechanism of GNR RTDs was demonstrated with their peak currents occurring at a similar bias (Vpeak) regardless of the shapes and temperatures. Furthermore, the impact of different ribbon widths at the contact/channel regions, which resulted in the different electronic structures, on electron transport was investigated at low temperature. A decrease in the channel width was found to increase the drive current while an increase in the contact width degraded it. The peak to valley ratio was degraded for both cases, while the Vpeak was increased. This study suggests that the device performance of GNR RTDs can be tuned by varying the ribbon width at the different sections, thereby providing great flexibility in future circuit designs. © 2009 The Japan Society of Applied Physics.