Abstract2D Semiconductors are promising in the development of next‐generation photodetectors. However, the performances of 2D photodetectors are largely limited by their poor light absorption (due to ultrathin thickness) and small detection range (due to large bandgap). To overcome the limitations, a strain‐plasmonic coupled 2D photodetector is designed by mechanically integrating monolayer MoS2 on top of prefabricated Au nanoparticle arrays. Within this structure, the large biaxial tensile strain can greatly reduce the MoS2 bandgap for broadband photodetection, and at the same time, the nanoparticles can significantly enhance the light intensity around MoS2 with much improved light absorption. Together, the strain‐plasmonic coupled photodetector can broaden the detection range by 60 nm and increase the signal‐to‐noise ratio by 650%, representing the ultimate optimization of detection range and detection intensity at the same time. The strain‐plasmonic coupling effect is further systematically characterized and confirmed by using Raman and photoluminescence spectrophotometry. Furthermore, the existence of built‐in potential and photo‐switching behavior is demonstrated between the strained and unstrained region, constructing a self‐powered homojunction photodetector. This approach provides a simple strategy to couple strain effect and plasmonic effect, which can provide a new strategy for designing high‐performance and broadband 2D optoelectronic devices.

Carbon nanotubes (CNTs) have a well-defined nanostructure to exhibit high electrical conductivity and chemical stability, and have been used as an advanced material to make electrodes of super-capacitor. Graphene nanoribbons (GNRs), as manufactured by unzipping the CNTs, have more flexible adjustable electrical properties than CNTs, and are regarded an even more promising material for super-capacitor electrodes. This paper presented a series of attempts to prepare GNRs by chemically treating multi-walled carbon nanotubes (MWCNTs); this is, an Oxidation-Reduction method was tried to make GNRs by unzipping MWCNTs longitudinally. Efforts were made in various trials to find conditions for Oxidation-Reduction processes to unzip MWCNTs.. With scanning electron microscopy, transmission electron microscopy, X-ray diffraction etc., characterization was performed to analysis the produced GNRs' micro-and nano-structure. Experiment was also carried out for its electro-chemical performance in the cyclic voltammetry (CV) and galvanostatic charge-discharge tests. Results as obtained so far showed that the super-capacitor electrodes as made with GNRs appeared to have higher electro-chemical performance than the MWCNTs electrodes.

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Monolayer-thick hexagonal boron nitride (h-BN) is grown on graphene on SiC(0001), by exposure of the graphene to borazine, (BH)3(NH)3, at 1100 C. The h-BN films form ~2-m size grains with a preferred orientation of 30 relative to the surface graphene. Low-energy electron microscopy is employed to provide definitive signatures of the number and composition of twodimensional (2D) planes across the surface. These grains are found to form by substitution for the surface graphene, with the C atoms produced by this substitution then being incorporated below the h-BN (at the interface between the existing graphene and the SiC) to form a new graphene plane. * feenstra@cmu.edu

Molybdenum selenide (MoSe 2 ) has been extensively studied in recent years due to its strong absorption for sunlight and unique band structure. Herein, a self-assembly three-dimensional (3D) MoSe 2 nano owers were prepared by a two-step process. Signi cantly, the photodetection device based on MoSe 2 nano owers exhibited a maximum responsivity about 12.39mA/W and a rapid photo-response time about 0.15s at 0V bias under simulated sunlight exposure bene ting from its large speci c surface area and unique morphologic structure. Meanwhile, we demonstrated the outstanding stability after two weeks of the photodetection device. In this way, the MoSe 2 nano ower-based photodetectors enriched the basic research of molybdenum selenide and provided some reference for the following researches based on molybdenum selenide.