Sub-Maxwellian Source Injection and Negative Differential Transconductance in Decorated Graphene Nanoribbons

The precise engineering of the graphene crystal structure at the atom level, enabled by the recent advances in approaches to synthesis, has driven a renewed surge of interest in graphene nanoribbons (GNRs), the electronic properties of which can be tuned by the arrangement of atoms at their edges. This technological option opens up the possibility of devising alternative devices based on carrier transport through topological states. In this work, by means of multiscale calculations, we investigate field-effect transistors based on topological GNRs with shaped edges, demonstrating the possibility of obtaining large negative differential transconductance effects, beating the Boltzmann limit for thermionic injection.