a scientist

We present the experimental synthesis of one-dimensional (1D) van der Waals heterostructures, a class of materials where different atomic layers are coaxially stacked. We demonstrate the growth of single-crystal layers of hexagonal boron nitride (BN) and molybdenum disulfide (MoS₂) crystals on single-walled carbon nanotubes (SWCNTs). For the latter, larger-diameter nanotubes that overcome strain effect were more readily synthesized. We also report a 5-nanometer–diameter heterostructure consisting of an inner SWCNT, a middle three-layer BN nanotube, and an outer MoS₂ nanotube. Electron diffraction verifies that all shells in the heterostructures are single crystals. This work suggests that all of the materials in the current 2D library could be rolled into their 1D counterparts and a plethora of function-designable 1D heterostructures could be realized.

Nature Electronics, Published online: 30 September 2019; doi:10.1038/s41928-019-0302-6

Graphene-based Hall magnetometers can be used to study the magnetization of two-dimensional ferromagnets.

Nanoscale tweezers for single-cell biopsies

Nanoscale tweezers for single-cell biopsies, Published online: 03 December 2018; doi:10.1038/s41565-018-0315-8

A nanotweezer system based on dielectrophoresis can trap, manipulate and extract biomolecules and organelles in living cells at physiological conditions with high spatiotemporal resolution and minimal invasiveness.

Two-dimensional (2D) semiconductors—atomic layers of materials with covalent intra-layer bonding and weak (van der Waals or quadrupole) coupling between the layers—are a new class of materials with great potential for optoelectronic applications. Among those, a special position is now being taken by post-transition metal chalcogenides (PTMC), InSe and GaSe. It has recently been found (Bandurin et al 2017 Nat. Nanotechnol . 12 223–7) that the band gap in 2D crystals of InSe more than doubles in the monolayer compared to thick multilayer crystals, while the high mobility of conduction band electrons is promoted by their light in-plane mass. Here, we use Raman and PL measurements of encapsulated few layer samples, coupled with accurate atomic force and transmission electron microscope structural characterisation to reveal new optical properties of atomically thin GaSe preserved by hBN encapsulation. The band gaps we observe complement the spectral range provided...

III–IV layered materials such as indium selenide have excellent photoelectronic properties. However, synthesis of materials in such group, especially with a controlled thickness down to monolayer, still remains challenging. Herein, we demonstrate the successful synthesis of monolayer InSe by physical vapor deposition (PVD) method. The high quality of the sample was confirmed by complementary characterization techniques such as Raman spectroscopy, atomic force microscopy (AFM) and high resolution annular dark field scanning transmission electron microscopy (ADF-STEM). We found the co-existence of different stacking sequence ( β - and γ -InSe) in the same flake with a sharp grain boundary in few-layered InSe. Edge reconstruction is also observed in monolayer InSe, which has a distinct atomic structure from the bulk lattice. Moreover, we discovered that the second-harmonic generation (SHG) signal from monolayer InSe shows large optical second-order susceptibility that is...

Electric-field switching of two-dimensional van der Waals magnets

Electric-field switching of two-dimensional van der Waals magnets, Published online: 12 March 2018; doi:10.1038/s41563-018-0040-6

The application of electric fields enables reversible switching of the magnetic order of CrI3 bilayers between antiferromagnetic and ferromagnetic states.

Vapour–liquid–solid growth of monolayer MoS₂ nanoribbons

Vapour–liquid–solid growth of monolayer MoS₂ nanoribbons, Published online: 23 April 2018; doi:10.1038/s41563-018-0055-z

Monolayer MoS2 can be laterally grown in the vapour–liquid–solid mode, forming highly crystalline nano- and microribbon structures.

Present status and future prospects of perovskite photovoltaics

Present status and future prospects of perovskite photovoltaics, Published online: 23 April 2018; doi:10.1038/s41563-018-0071-z

Solar cells based on metal halide perovskites continue to approach their theoretical performance limits thanks to worldwide research efforts. Mastering the materials properties and addressing stability may allow this technology to bring profound transformations to the electric power generation industry.

An unusual continuous paramagnetic-limited superconducting phase transition in 2D NbSe ₂

An unusual continuous paramagnetic-limited superconducting phase transition in 2D NbSe₂, Published online: 30 April 2018; doi:10.1038/s41563-018-0061-1

Tunnelling spectroscopy reveals a continuous closing of the superconducting gap at low temperature and high in-plane magnetic field in few-layer NbSe2, due to the Ising spin–orbit coupling of these materials.