Thermal hot-carrier breakdown in metasurface structures based on coplanar arrays of graphene microribbons connected with wide-gap bridges

We analyze the thermal and electrical characteristics of the metasurface composed of a coplanar interdigital array of the graphene microribbons (GMRs) connected by nanobridges (NBs). These nanobridges could be implemented using graphene nanoribbons (GNRs) or black-arsenic-phosphorus (b-AsP) nanostructures. When a bias voltage applied between neighboring GMRs, it induces electron and hole two-dimensional systems within the GMRs, leading to thermionic currents that flow through the connecting NB resulting in the self-heating effect. This self-heating effect increases the thermionic currents, creating an effective positive feedback loop between the carrier effective temperature and the injected currents, and the bias voltage. This mechanism may lead to thermal breakdown enabling threshold behavior of current–voltage characteristics and yielding an S-shaped response. The devices based on the GMR/GNR and GMR/AsP metasurface structures can serve as fast voltage-controlled current switches, sensors, thermal terahertz and infrared sources, and among other applications.