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

TL;DR

This paper investigates the thermal and electrical behavior of graphene-based metasurfaces with coplanar arrays of microribbons connected by nanobridges, revealing mechanisms for thermal breakdown and potential applications in switches and sensors.

Contribution

It introduces a novel analysis of thermal breakdown mechanisms in graphene metasurfaces with nanobridge connections, highlighting their threshold current-voltage behavior and device applications.

Findings

Self-heating induces positive feedback in thermionic currents.

Thermal breakdown leads to S-shaped current-voltage characteristics.

Potential for fast voltage-controlled switches and infrared sources.

Abstract

We analyze the thermal and electrical characteristics of the metasurface consisting of the coplanar interdigital array of the graphene microribbons (GMRs) connected by nanobridges (NBs). These nanobridges could be implemented using graphene nanoribbons (GNRs), single-wall semiconducting carbon nanotubes (CNTs), or black-arsenic-phosphorus (b-AsP) nanostructures. The bias voltage applied between neighboring GMRs indices electron and hole two-dimensional systems in the GMRs and induces thermionic currents flowing through connecting NBs. The resulting self-heating increases thermionic currents providing an effective positive feadback between the carrier effective temperature and the injected currents. This mechanism may lead to thermal breakdown enabling threshold behavior of current-voltage characteristics and resulting in the S-shape of these characteristics. The devices based on the GMR/GNR, GMR/CNT, and GMR/AsP metasurface structures can be used as fast voltage-controlled current switches, sensors, thermal terahertz and infrared sources, and other devices.