Atomically thin 2D-layered transition-metal dichalcogenides have been studied extensively in recent years because of their intriguing physical properties and promising applications in nanoelectronic devices. Among them, ReSe2 is an emerging material that exhibits a stable distorted 1T phase and strong in-plane anisotropy due to its reduced crystal symmetry. Here, the anisotropic nature of ReSe2 is revealed by Raman spectroscopy under linearly polarized excitations in which different vibration modes exhibit pronounced periodic variations in intensity. Utilizing high-quality ReSe2 nanosheets, top-gate ReSe2 field-effect transistors were built that show an excellent on/off current ratio exceeding 10(7) and a well-developed current saturation in the current-voltage characteristics at room temperature. Importantly, the successful synthesis of ReSe2 directly onto hexagonal boron nitride substrates has effectively improved the electron motility over 500 times and the hole mobility over 100 times at low temperatures. Strikingly, corroborating with our density-functional calculations, the ReSe2-based photodetectors exhibit a polarization-sensitive photoresponsivity due to the intrinsic linear dichroism originated from high in-plane optical anisotropy. With a back-gate voltage, the linear dichroism photodetection can be unambiguously tuned both in the electron and hole regime. The appealing physical properties demonstrated in this study clearly identify ReSe2 as a highly anisotropic 2D material for exotic electronic and optoelectronic applications.

Recently, layered two-dimensional ferromagnetic materials (2D FMs) have attracted a great deal of interest for developing lowdimensional magnetic and spintronic devices. Mechanically exfoliated 2D FMs were discovered to possess ferromagnetism down to monolayer. It is therefore of great importance to investigate the distinct magnetic properties at low dimensionality. Here, we report the wafer-scale growth of 2D ferromagnetic thin films of Fe 3 GeTe 2 via molecular beam epitaxy, and their exotic magnetic properties can be manipulated via the Fe composition and the interface coupling with antiferromagnetic MnTe. A 2D layer-by-layer growth mode has been achieved by in situ reflection high-energy electron diffraction oscillations, yielding a well-defined interlayer distance of 0.82 nm along {002} surface. The magnetic easy axis is oriented along c-axis with a Curie temperature of 216.4 K. Remarkably, the Curie temperature can be enhanced when raising the Fe composition. Upon coupling with MnTe, the coercive field dramatically increases 50% from 0.65 to 0.94 Tesla. The large-scale layer-by-layer growth and controllable magnetic properties make Fe 3 GeTe 2 a promising candidate for spintronic applications. It also opens up unprecedented opportunities to explore rich physics when coupled with other 2D superconductors and topological matters.

The photosynthetic parameters of Pinus taeda foliage originally presented in Table 2 were shown with incorrect units. The units for Ane t (at Ca=350 and 550 gmol mol-l), Asa t and VCma x should be gmol CO 2 m -2 s -1. The units shown in all of the original figures were correct. We sincerely regret any confusion that may have arisen over this.

Transitional metal ditelluride WTe has been extensively studied owing to its intriguing physical properties like nonsaturating positive magnetoresistance and being possibly a type-II Weyl semimetal. While surging research activities were devoted to the understanding of its bulk properties, it remains a substantial challenge to explore the pristine physics in atomically thin WTe. Here, we report a successful synthesis of mono- to few-layer WTe via chemical vapor deposition. Using atomically thin WTe nanosheets, we discover a previously inaccessible ambipolar behavior that enables the tunability of magnetoconductance of few-layer WTe from weak antilocalization to weak localization, revealing a strong electrical field modulation of the spin-orbit interaction under perpendicular magnetic field. These appealing physical properties unveiled in this study clearly identify WTe as a promising platform for exotic electronic and spintronic device applications.