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. © 2026 Author(s).

The terahertz (THz) frequency range (0.1-10 THz) bridges the electronic and photonic spectral domains and offers key opportunities for high-speed communication, sensing, and spectroscopy. However, the realization of compact, coherent, and room-temperature THz sources and detectors remains still a long-standing challenge. Recent advances in two-dimensional (2D) materials, hosting graphene-like massless Dirac fermions, have opened some new paths toward overcoming this limitation. This paper reviews recent advances in the physics of Dirac plasmons in graphene and related 2D heterostructure materials and their THz device applications. It first outlines the fundamentals of 2D plasmon hydrodynamics, nonlinearities, and current-driven instabilities, including Dyakonov-Shur Ryzhii-Satou-Shur, and Cherenkov-type mechanisms. A new mechanism, Coulomb drag instability, recently discovered by the authors, is theoretically shown to provide the largest plasmonic gain among these mechanisms, offering a new route to efficient THz amplification and lasing. Its experimental verification is currently in progress. The review also discusses graphene-based plasmonic lasers, amplifiers, and detectors, and recent developments in graphene/black-arsenic-phosphorus heterostructures that enable band-structure and plasmonic engineering. Finally, topological-insulator-based heterostructures are introduced as promising material systems. These advances demonstrate that Dirac plasmon physics provides a robust foundation for next-generation THz device technology.

[Invited] This paper reviews recent advances on the concepts of graphene/black-phosphorene-arsenic two-dimensional heterostructures for terahertz (THz) and infrared (IR) detectors and emitters focusing on our proposal, device modeling, and future prospects. Due to the gapless energy spectrum of the graphene layers (GLs), the interband absorption and emission of photons and plasmons in the GLs takes place in wide spectral range, including the THz and IR ranges. The energy gap of the emerging black-Phosphorus (b-P), black-Arsenic (b-As), and the compounds b-P1-xAsx varies from 0.15 to 1.2 eV, depending on the number of the atomic layers and the composite fraction of x. Combining GLs with the b-P, b-As, and b- P1-xAsx layers gives rise to various performance boosting effects in the THz detectors and light sources. © 2025 SPIE.