range, enhancing its compactness, and reducing its power consumption. The conventional photoelectric mechanism of high-energy radiation (ultraviolet, visible, and near-infrared band) involves a photon that excites an electron across the bandgap between the valence and conduction bands (photon energy ℏω > E g ), and then separating by the semiconductor junction or bias to produce photocurrent. However, at longer wavelength bands, this mechanism is considerably inhibited by the lack of efficient charge separation in materials with suitable bandgap and low dark current to match with the lowphoton energy and high signal-to-noise ratio. Despite the promising application prospects of terahertz (THz) technology ranging from security to medicine, the innovation of sensitive, high-speed, broadband detectors operating at room temperature is greatly challenging. [1][2][3][4] Since the energy of terahertz photon energy (0.1-10 THz, 41-0.41 meV) is orders of magnitude lower than the room-temperature thermal energy, it fails to achieve uncooled interband, extrinsic, or intersubband transitions at υ < 10 ΤΗz. [5][6][7] The current commercial thermal-type terahertz detectors, such as Golay cell, thermocouple, and pyroelectric and bolometric detectors, are unable to attain a reasonable trade-off between sensitivity, operatingThe high-performance detector that operates at the low-photon-energy range (≈meV) of the electromagnetic spectrum at room temperature remains in urgent demand for application in a variety of important sectors, including 6G communications, security, sensing, medicine, space science, etc. The vast range of 2D-layered nanomaterials and their distinct layer structures provide an ideal foundation for the manufacture of sophisticated photodetectors and detectors with convenient fabrication methods. In this paper, the direct detection of terahertz waveband dominated by the bolometer effect and photo-thermoelectric effect is demonstrated, which is endowed with a versatile integration of 2H-NbSe 2 in terms of planar and vertical van der Waals structures. This 2H-NbSe 2 -based device can detect broadband long wavelength due to the bolometer effect, and the van der Waals heterostructure-based device exhibits excellent sensitivity and self-powered photo-thermoelectric conversion with high responsivity (>735 V W −1 ), low response time (<1 µs), as well as low noise equivalent power (NEP < 50 pW Hz −0.5 ) at room temperature. The photodetector engineers versatile detection mechanisms, displaying low-energy photons on the hybrid integration of novel low-dimensional materials and providing an opportunity for the practical application of energy harvesting.

Recently, black arsenic has joined the novel 2-dimensional van der Waals layered material family as a promising candidate for electronic and photonic applications owing to the tunable bandgap with layers, high carrier mobility, and anisotropic transport feature. To date, the extraordinary technological potential of black arsenic engineering nanophotoelectronic devices in the range from visible to near-infrared wavelength has not been reported. Here, we succeed in devising black arsenic visible–infrared detectors at the range from 520 to 1,550 nm, exhibiting a photoresponsivity of 0.4 A·W −1 and a detective of 1.37 × 10 8 Jones. Our studies underscore black arsenic as an emerging 2-dimensional van der Waals layered material for optoelectronic applications such as near-infrared sensing and imaging.

Graphene, known for its high carrier mobility and broad spectral response range, has proven to be a promising material in photodetection applications. However, its high dark current has limited its application as a high-sensitivity photodetector at room temperature, particularly for the detection of low-energy photons. Our research proposes a new approach for overcoming this challenge by designing lattice antennas with an asymmetric structure for use in combination with high-quality monolayers of graphene. This configuration is capable of sensitive detection of low-energy photons. The results show that the graphene terahertz detector-based microstructure antenna has a responsivity of 29 V·W−1 at 0.12 THz, a fast response time of 7 μs, and a noise equivalent power of less than 8.5 pW/Hz1/2. These results provide a new strategy for the development of graphene array-based room-temperature terahertz photodetectors.