2D materials - Page 5

A team of scientists at Johns Hopkins University in the U.S. has designed a mass-production strategy to create monolayer graphene-based reversible self-folding structures. The material may find potential uses in microfluidics and micromechanical systems.

Mechanism and versatility of self‐folding SU8 films. Image from article

As proof of concept, the team achieved complex and functional devices in the form of rings, polyhedra, flowers and origami birds. They then integrated gold electrodes to the constructs to improve their detection sensitivity. The experiments suggest a comprehensive framework to rationally design and fabricate scalable and complex, 3D, self-folding optical and electronic devices by folding 2D monolayer graphene.

A research team led by the University of Washington recently reported that carefully constructed stacks of graphene can exhibit highly correlated electron properties. The team also found evidence that this type of collective behavior likely relates to the emergence of exotic magnetic states.

We’ve created an experimental setup that allows us to manipulate electrons in the graphene layers in a number of exciting new ways, said co-senior author Matthew Yankowitz, a UW assistant professor of physics and of materials science and engineering. Yankowitz led the team with co-senior author Xiaodong Xu, a UW professor of physics and of materials science and engineering.

Researchers at Chalmers University in Sweden have recently reported a facile and controllable anisotropic wet etching method that allows scalable fabrication of transition metal dichalcogenides (TMD) metamaterials with atomic precision. The team says that this new method has great potential for various layered structures like MoS₂ and WS₂ and graphene.

Process of etching hexagonal nanostructures in TMD materials. Image from article

They showed that materials can be etched along certain crystallographic axes, such that the obtained edges are nearly atomically sharp and exclusively zigzag-terminated. This results in hexagonal nanostructures of predefined order and complexity, including few-nanometer-thin nanoribbons and nanojunctions. Thus, this method enables future studies of a broad range of metamaterials through atomically precise control of the structure.

Graphene raw materials supplier First Graphene and UK-based specialist materials manufacturer M&I Materials have agreed to collaborate to develop an extended range of graphene-enhanced products.

Both companies are partners at Manchester’s Graphene Engineering and Innovation Centre (GEIC), a facility dedicated to the commercialization of graphene. The GEIC has played a big part in enabling this collaboration and has benefited both parties in terms of the close working relationship at the same location and the extensive facilities and support available on site.

Graphene buckles when cooled while attached to a flat surface, resulting in patterns that could benefit the search for novel quantum materials and superconductors, according to a recent Rutgers-led research.

Quantum materials host strongly interacting electrons with special properties, such as entangled trajectories, that could provide building blocks for super-fast quantum computers. They also can become superconductors that could slash energy consumption by making power transmission and electronic devices more efficient.

Physicists at the University of Basel have created a novel structure with the ability to absorb almost all light of a selected wavelength, by layering different 2D materials: graphene and molybdenum disulfide.

Schematic illustration of the electron-hole pairs (electron: pink, hole: blue), which are formed by absorption of light in the two-layer molybdenum disulfide layer. Credit: Nadine Leisgang and Lorenzo Ceccarelli, Department of Physics, University of Basel

The new structure's particular properties reportedly make it a candidate for applications in optical components or as a source of individual photons, which play a key role in quantum research.

Researchers at TU Wien have designed a nano-structuring method, with which certain layers of a material can be perforated with extreme precision while others are left completely untouched, even though the projectile penetrates all layers.

The projectile penetrates all layers, but only in the top layer, a big hole is created. The graphene below remains intact. Credit: TU Wien

This is made possible with the help of highly charged ions - they can be used to selectively process the surfaces of novel 2D material systems, for example to anchor certain metals on them, which can then serve as catalysts.

Materials scientists at Rice University and the University of Pennsylvania have published an article calling for a collective, global effort to fast-track the mass production of 2D materials like graphene and molybdenum disulfide.

In their perspective article, journal editor-in-chief Jun Lou and colleagues make a case for a focused, collective effort to address the research challenges that could clear the way for large-scale mass production of 2D materials.

New study by Caltech shows that superconductivity in twisted bilayer graphene can exist away from the magic angle when coupled to a two-dimensional semiconductor

In 2018, researchers made the surprising discovery that when you layer two sheets of single-atom-thick graphene atop one another and rotate them by precisely 1.05 degrees with respect to one another, the resulting bilayer material takes on new properties: when the density of electrons in the material is increased through the application of a voltage on a nearby electrode, it becomes a superconductor—electrons can flow freely through the material, without resistance. However, with a slight change in electron density, the bilayer becomes an insulator and prevents the flow of electrons.

The Graphene Flagship has announced 16 New FLAG-ERA projects, that cover a broad range of topics, from fundamental to applied research. These projects which will become Partnering Projects of the Graphene Flagship receiving around €11 million in funding overall.

Bringing together a diverse range of European knowledge and expertise, FLAG-ERA is an ERA-NET (European Research Area Network) initiative that aims to create synergies between new research projects and the Graphene Flagship and Human Brain Project.