Photodetectors (PDs) leveraging two-dimensional (2D) materials and topological materials have garnered substantial interest due to their exceptional electronic and optoelectronic characteristics. These materials, including 2D semimetals like graphene, semiconducting transition metal dichalcogenides, and topological insulators such as bismuth selenide, exhibit a broad array of bandgap values and unique photon interaction properties. To date, numerous high-performance PDs using these materials have been documented, showing significant potential in terahertz (THz) frequency applications. This review presents a comprehensive examination of PDs based on 2D and topological materials, focusing on the THz frequency. Initially, an insight into the photocurrent generation mechanisms within these materials is provided, alongside a discussion of the figure-of-merits, such as responsivity and detectivity, which are crucial for evaluating PD performance. The recent advancements in THz photodetection are then highlighted, noting exceptional attributes such as high sensitivity, ultrafast response, broad spectral operation, and anisotropic detection capabilities, based on cutting-edge devices. Early-stage applications and the integration potential of these PDs in various technologies are also explored. Concluding, the manuscript offers a forward-looking perspective, outlining ongoing challenges, future research directions, and practical advice for developing next-generation THz PDs, aiming to inspire continued innovation in this rapidly evolving field.

The trihexagonal tiling system exhibits strong electron-electron interactions, positioning it as a key condensed matter platform for studying geometrically frustrated lattices made up of corner-sharing triangles. Its phase-transition-driven lattice modulations enable Fermi surface reconstruction, while emergent van Hove singularities near the Fermi level and correlated band anomalies present critical challenges in understanding electronic interaction mechanisms. By combining temperature-dependent spectroscopy, angle-resolved photoemission, and density functional theory calculations, we demonstrate a 61-fold enhancement in terahertz direct detection mode, ultra-low noise (1.38 × 10⁻²⁵ A²/Hz) below phase transition temperature, and broadband operation up to 100 GHz in beat-note heterodyne mode. These results are directly correlated with the Fermi surface reconstruction induced by phase transitions. This work positions geometrically frustrated lattices as a powerful platform for studying correlated quantum phenomena, offering new pathways for the design of advanced quantum devices.

Studying the nonlinear photoresponse of different materials, including III-V semiconductors, two-dimensional materials and many others, is attracting burgeoning interest in the terahertz (THz) field. Especially, developing field-effect transistor (FET)-based THz detectors with preferred nonlinear plasma-wave mechanisms in terms of high sensitivity, compactness and low cost is a high priority for advancing performance imaging or communication systems in daily life. However, as THz detectors continue to shrink in size, the impact of the hot-electron effect on device performance is impossible to ignore, and the physical process of THz conversion remains elusive. To reveal the underlying microscopic mechanisms, we have implemented drift-diffusion/hydrodynamic models via a self-consistent finite-element solution to understand the dynamics of carriers at the channel and the device structure dependence. By considering the hot-electron effect and doping dependence in our model, the competitive behavior between the nonlinear rectification and hot electron-induced photothermoelectric effect is clearly presented, and it is found that the optimized source doping concentrations can be utilized to reduce the hot-electron effect on the devices. Our results not only provide guidance for further device optimization but can also be extended to other novel electronic systems for studying THz nonlinear rectification.

In the realm of wireless sensing, it is envisioned that sensing and communication functionalities will coexist and be fully integrated within a unified system. Future sensing systems thus necessitate detectors capable of operating at higher frequency bands—ranging from millimeter wave to terahertz (THz)—while delivering wider bandwidths, faster response rates, and enhanced functional integration. Dirac-source (DS) detectors use Dirac semimetals as hot-electron sources to capitalize on the low density of states (DOS) near the Dirac point, thereby effectively suppressing the formation of metal-induced gap states. Furthermore, when this architecture incorporates the inherent interlayer vertical electron transport of vertical van der Waals (vdW) heterostructures, it shows great promise for realizing low-power, post–Moore era sensing devices with superior injection and transport efficiencies. Here, we report a DS detector composed of the completely vertical gold/zirconium pentatelluride/graphene/gold structure (Au/ZrTe ₅ /graphene/Au) heterojunction, which harnesses strong localized fields to achieve high thermionic emission. The detector manifests outstanding performance in terms of remarkable responsivity, exceeds a peak of 1600 V/W from 0.02 to 0.5 THz at room temperature, has a fast response time less than 20 ns, and notably is capable for heterodyne mixing with intermediate frequency (IF) bandwidth larger than ±26.5 gigahertz. Our results not only shed a fresh light on DS dynamics in the terahertz region but also highlight the transformative potential of semimetal electronics for applications in wireless energy harvesting, communication, and imaging.

Terahertz technology has demonstrated immense potential across a wide range of applications, particularly in the realm of THz photodetection. However, state-of-the-art detectors typically face fundamental trade-offs among sensitivity, response speed, operating temperature, and spectral bandwidth. While previous studies have shown that graphene field-effect transistors (GFETs) exhibit a broadband, room-temperature photoresponse to THz radiation—often attributed to photothermoelectric (PTE) and plasma-wave rectification effects—the similar functional dependence of these mechanisms on the gate voltage has historically made it challenging to disentangle their individual contributions. In this study, we leverage monolayer graphene as the photoactive material to overcome these limitations within a single device architecture. We present a novel THz photodetector driven predominantly by the PTE effect, facilitated by a precisely designed counterclockwise spiral antenna. The demonstrated device achieves exceptional room-temperature sensitivity, featuring a minimum noise equivalent power (NEP) of 80.7 $\mathrm{p}\mathrm{W}/\sqrt{\mathrm{H}\mathrm{z}}$ alongside a rapid response time of less than 11 μs. Furthermore, by systematically analyzing the temporal response dynamics, we unambiguously identify the PTE effect as the dominant operating mechanism. These results provide a robust strategy for the development of high-performance, room-temperature THz optoelectronics, paving the way for advanced practical applications in high-capacity wireless communications and real-time THz imaging.