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The applications of graphene and transition metal dichalcogenides in electronics are limited by their zero-bandgap and low mobility, respectively. Here, the authors demonstrate the potential of an emerging layered material—black phosphorous—for thin film electronics and infrared optoelectronics.

Prokaryotic pan-genome analysis is crucial for understanding microbial diversity, however current analytical methods often struggle to balance accuracy and computational efficiency. Here the authors present a more precise, robust and scalable toolkit for large-scale pan genome analysis.

Layered black phosphorous has gained significant attention in the 2D materials community, and dynamical control of its bandgap is key to enable novel applications. Here, the authors demonstrate continuous electrical bandgap tuning using moderate displacement fields.

The contact resistance of a junction between graphene and palladium is shown to be strongly affected by carrier transport in graphene underneath the palladium, and is measured to be just two to three times larger than the minimum resistance achievable.

Researchers clarify damping pathways for mid-infrared graphene plasmons, including graphene intrinsic optical phonons and edge scattering. They also demonstrate the guiding of mid-infrared graphene plasmons in 50-nm-wide structures with an electromagnetic mode area of 10⁻³μm² and a propagation length of 200 nm.

Microcavity polaritons—the bosonic quasiparticles that result from strong light–matter coupling—are observed for the first time in a dielectric cavity containing a monolayer of molybdenum disulphide at room temperature.

Scientists report that the photovoltaic effect and a photo-induced bolometric effect, rather than thermoelectric effects, dominate the photoresponse during a classic photoconductivity experiment in biased graphene. The findings shed light on the hot-electron-driven photoresponse in graphene and its energy loss pathway via phonons.

Massless electrons in graphene exhibit a mass when considered as collective excitations known as plasmons.

A powerful strategy to leverage and combine the optoelectronic characteristics of different 2D materials is to stack them into vertical van der Waals heterostructures. This approach is now used to realize efficient light-emitting devices.

All-electrical excitation of the hyperbolic phonon polaritons in hexagonal boron nitride by drifting charge carriers in nearby graphene results in electroluminescence at mid-infrared frequencies.

A compact on-chip polarimeter can be created using subpixels made from metasurface photodetectors and a machine learning algorithm.

Silicon photonic circuits offer a promising solution for the interconnect bottleneck for advanced computing systems, but they typically require additional materials, such as germanium for photodetection. An all-silicon receiver capable of handling a data stream at 1.28 terabits per second is paving the way for future optical interconnects.

Controlling the periodicity of synthesized moiré materials is vital to harness their unique physics. Here the authors realize the van der Waals epitaxy of tunable moiré heterostructures and reveal the epitaxial science governing their formation.

A large-angle twist between two bilayer graphene films makes a sensitive and broadband infrared–terahertz detector as a result of interlayer screening and a crystal field-induced bandgap.

The low mobility measured for molybdenum disulphide layers grown using chemical vapour deposition limits the applications of these promising materials. Here, the authors show that band tail states play an important role on its electronic properties and that the band mobility is significantly higher.

Controlling the vapour transport mode with sustained release of precursor species allows for the growth of single-crystalline black phosphorus and black phosphorus–arsenic thin films on the millimetre scale.

A single-photodetector spectrometer based on black phosphorus is demonstrated in the wavelength range from 2 to 9 μm. The footprint is 9 × 16 μm². The spectrometer is free from bulky interferometers and gratings, and is electrically reconfigurable.

Tunable quantum geometric properties of moiré graphene enable the use of a convolutional neural network to simultaneously decipher the light polarization, power and wavelength in a subwavelength-scale smart device.

Excitonic states with hybrid dimensionality in layered silicon diphosphide exhibit interesting features such as linearly dichroic photoluminescence and unusually strong exciton–phonon coupling.

A system of patterned graphene nanoresonators/nanoribbons can be used as an efficient mid-infrared detector, based on plasmonic resonant absorption and subsequent carrier thermalization.

The bandgap of ultrathin black phosphorus can be tuned by a vertical electric field. Here, the authors leverage such electric field to extend the photoresponse of a black phosphorus photodetector to 7.7 μm, opening the doors to various mid-infrared applications.

Scientist and engineer who helped shape semiconductor technologies.

Orthogonal acute inducible degradation cell lines are used to delineate the mechanisms of how extrusive cohesin, cohesive cohesin and condensin interact to remodel chromosome architecture from interphase to mitosis.

Field-effect transistors made from graphene act as photodetectors at frequencies up to 40 GHz, demonstrating the advantage offered by graphene for photonic applications.

Silicon photonics is deemed to be the solution for dense on-chip optical networks. Now, by using cascaded silicon microring resonators, scientists demonstrate an ultracompact switch that is insensitive to wavelength and temperature. The switch also has fast error-free operation in multiple 40-Gbit s⁻¹ optical channels and is suitable for scalable networks.

To integrate microchips with optical communications a photodetector is required to mediate the optical and electronic signals. Although germanium photodetectors are compatible with silicon their performance is impaired by poor intrinsic noise. Here the noise is reduced by nanometre engineering of optical and electrical fields to produce a compact and efficient photodetector.

Polarization-resolved photoluminescence measurements reveal the anisotropic character of excitons in monolayer black phosphorus, which are found to have a large binding energy.

An attractive method to fabricate graphene transistors is transferring high-quality graphene sheets to a suitable substrate. This study identifies diamond-like carbon as a new substrate for graphene devices. It is attractive as few sources for scattering are expected at the interface that may lead to deterioration of device properties. Graphene transistors operating at radio frequencies with cutoff as high as 155 GHz and with scalable gate length are demonstrated. Unlike conventional semiconductor devices, the high-frequency performance of the graphene devices exhibits little temperature dependence down to 4.3 K, providing a much larger operation window than conventional devices.

The resonant frequency and magnitude of graphene plasmons in graphene/insulator stacks depend on the layer number, which allows tunable filters and polarizers to be built.

A graphene-based photodetector with unprecedented photoresponsivity and the ability to perform error-free detection of 10 Gbit s⁻¹s data streams is demonstrated. The results suggest that graphene-based photonic devices have a bright future in telecommunications and other optical applications.

Semiconducting carbon nanotubes have a direct bandgap, which means that they could form the basis of nanoscale light sources. However, nanotubes tend to emit light over a broad range of wavelengths and directions. Placing the nanotube in a microcavity reduces the spectral width of the output and makes the emission highly directional. This microcavity-controlled, current-driven on-chip emitter is thus an important first step in the development of nanotube-based nanophotonic devices.

The optical properties of graphene and emerging two-dimensional materials including transition metal dichalcogenides are reviewed with an emphasis on nanophotonic applications.

By patterning graphene with sub-wavelength features to introduce plasmonic modes, its optical properties can be tailored. Freitag et al. show how tunable plasmons in graphene nanoribbons can be exploited to form polarization-sensitive graphene photodetectors in the mid-infrared spectral region.

Owing to the superlattice-induced bandgap and superlattice-enhanced density of states, small-twist-angled (<2°) bilayer graphene exhibits a strong gate-tunable photoresponse in the mid-infrared regime of 5 to 12 μm, reaching an extrinsic peak responsivity of 26 mA W⁻¹ at 12 μm.

Layered black phosphorus and its isoelectronic group IV monochalcogenides have distinctive physical properties arising from their unusual crystal symmetries. This Review discusses some of the interesting physical phenomena, possible device applications and future research directions for this group of materials.

Semimetal photodetectors provide high-speed and broadband operation but suffer from serious drawbacks such as high dark currents. This Perspective discusses the opportunities offered by topological effects to overcome these issues and improve their performance.