Graphene has emerged as a promising material for photonic applications fuelled by its superior electronic and optical properties. However, the photoresponsivity is limited by the low absorption cross-section and ultrafast recombination rates of photoexcited carriers. Here we demonstrate a photoconductive gain of ∼105 electrons per photon in a carbon nanotube–graphene hybrid due to efficient photocarriers generation and transport within the nanostructure. A broadband photodetector (covering 400–1,550 nm) based on such hybrid films is fabricated with a high photoresponsivity of >100 A W−1 and a fast response time of ∼100 μs. The combination of ultra-broad bandwidth, high responsivities and fast operating speeds affords new opportunities for facile and scalable fabrication of all-carbon optoelectronic devices.

Atomically thin layered two-dimensional (2D) materials have provided a rich library for both fundamental research and device applications. Bandgap engineering and controlled material response can be achieved from artificial heterostructures. Recently, excitonic lasers have been reported using transition metal dichalcogenides; however, the emission is still the intrinsic energy bandgap of the monolayers. Here, we report a room temperature interlayer exciton laser with MoS2/WSe2 heterostructures. The onset of lasing was identified by the distinct kink in the “L-L” curve and the noticeable spectral linewidth collapse. Different from visible emission of intralayer excitons in monolayer components, our laser works in the infrared range, which is fully compatible with the well-established technologies in silicon photonics. Long lifetime of interlayer excitons relaxes the requirement of the cavity quality factor by orders of magnitude. Room temperature interlayer exciton lasers might open new perspectives for developing coherent light sources with tailored optical properties on silicon photonics platforms.

2D layered materials based p–n junctions are fundamental building block for enabling new functional device applications with high efficiency. However, due to the lack of controllable doping technique, state‐of‐the‐art 2D p–n junctions are predominantly made of van der Waals heterostructures or electrostatic gated junctions. Here, the authors report the demonstration of a spatially controlled aluminum doping technique that enables a p–n homojunction diode to be realized within a single 2D black phosphorus nanosheet for high performance photovoltaic application. The diode achieves a near‐unity ideality factor of 1.001 along with an on/off ratio of ≈5.6 × 103 at a low bias of 2 V, allowing for low‐power dynamic current rectification without signal decay or overshoot. When operated under a photovoltaic regime, the diode's dark current can be significantly suppressed. The presence of a built‐in electric field additionally gives rise to temporal short‐circuit current and open‐circuit voltage under zero external bias, indicative of its enriched functionalities for self‐powered photovoltaic and high signal‐to‐noise photodetection applications.

Measurement of nonlinear response offers powerful probes of material propertiesnot accessible at linear order, as they follow distinct symmetry requirements 1,2,3,4,5,6 . For instance, unlike the linear Hall effect, the second-order nonlinear Hall effect typically requires the breaking of inversion symmetry rather than time reversal symmetry 1 , and its successful detection in recent experiments on ultrathin WTe2 has attracted significant attention 7,8 . This second-order nonlinear Hall effect could be used to probe the Berry curvature, a band geometric property, in non-magnetic materials, just like the anomalous Hall effect being used to probe the Berry curvature in magnetic materials 9,10 . As another intrinsic band geometric property, the Berry-connection polarizability tensor was theoretically predicted to play a crucial role in high-order responses 11 but not yet experimentally demonstrated. Here, we report for the first time a high-order nonlinear Hall effect in multi-layer 𝑻 𝒅 -MoTe2 samples. Unprecedently, the third-order Hall