Researchers at Spain's IMDEA Nanoscience, Donostia International Physics Center, Ikerbasque and Poland's University of Opole have developed an analytical method to explain the formation of a quasi-perfect 1D moiré pattern in twisted bilayer graphene. The pattern, naturally occurring in piled 2D materials when a strain force is applied, represents a set of channels for electrons.

The team studied the effects of strain in moiré systems composed of honeycomb lattices. The scientists elucidated the formation of almost perfect one-dimensional moiré patterns in twisted bilayer systems. The formation of such patterns is a consequence of an interplay between twist and strain which gives rise to a collapse of the reciprocal space unit cell. As a criterion for such collapse, they found a simple relation between the two quantities and the material specific Poisson ratio. The induced one-dimensional behavior is characterized by two, usually incommensurate, periodicities.

Researchers at Graphenea, University of Utah and Kairos Sensors have examined a perovskite-based graphene field effect transistor (P-GFET) device for X-ray detection. 

The device architecture consisted of a commercially available GFET-S20 chip, produced by Graphenea, with a layer of methylammonium lead iodide (MAPbI₃) perovskite spin coated onto the top of it. This device was exposed to the field of a molybdenum target X-ray tube with beam settings between 20 and 60 kVp (X-ray tube voltage) and 30–300 μA (X-ray tube current). Dose measurements were taken with an ion-chamber and thermo-luminescent dosimeters and used to determine the sensitivity of the device as a function of the X-ray tube voltage and current, as well as source-drain voltage. 

Researchers at Texas A&M University recently discovered that when charging a supercapacitor, it stores energy and responds by stretching and expanding. This insight could be help design new materials for flexible electronics or other devices that need to be both strong and store energy efficiently.

The team measured stresses that developed in graphene-based supercapacitor electrodes and correlated the stresses to how ions move in and out of the material. For example, when a capacitor is cycled, each electrode stores and releases ions that can cause it to swell and contract. According to the team, this repeated motion can cause the build-up of mechanical stresses, resulting in device failure. To combat this, the research looks to create an instrument that measures mechanical stresses and strains in energy storage materials as they charge and discharge.

A team of scientists, led by David Serrate, CSIC scientist at the Instituto de Nanociencia y Materiales de Aragón, INMA (a joint institute of the CSIC and the University of Zaragoza), has imaged for the first time the magnetic behavior of a graphene nanostructure. The team has not only revealed the magnetic state of narrow graphene ribbons (~2 nm), but has also shown the method they developed to magnetically characterize any planar nanographene.

Starting with a specifically designed organic precursor, the researchers synthesized the ribbons directly onto a magnetic surface, obtaining atomically precise edges that contain an alternating sequence of zig-zag graphene segments. This geometry strongly confines the graphene electron cloud around the edge, which causes the instability responsible for the intrinsic magnetism of the graphene nanostructure –a remarkable fact taking into account that the ribbon is formed just by non-magnetic carbon and hydrogen atoms.

Researchers at China's Guilin University of Electronic Technology, China Nonferrous Metals (Guilin) Geology and Mining Co., Ltd., Dalian University of Technology and Reliability Physics and Application Technology of Electronic Component Key Laboratory have developed a method to enhance the energy storage performance of lithium-ion batteries, involving the modification of natural graphite through irradiation with a high-current pulsed electron beam (HCPEB).

The method relies on HCPEB to prepare self-supporting graphene without pollution irradiation. The team reported that graphite was instantaneously transformed into defective graphene structures and that the resulting graphene electrodes exhibited excellent lithium storage and cycling properties.

Researchers at MIT, Harvard and Japan's National Institute for Materials Science have reported a surprising property in graphene: When stacked in five layers, in a rhombohedral pattern, graphene displays a rare, “multiferroic” state, in which the material exhibits both unconventional magnetism and an exotic type of electronic behavior, which the team has named "ferro-valleytricity".

“Graphene is a fascinating material,” said Long Ju, assistant professor of physics at MIT. “Every layer you add gives you essentially a new material. And now this is the first time we see ferro-valleytricity, and unconventional magnetism, in five layers of graphene. But we don’t see this property in one, two, three, or four layers”. The discovery could promote ultra-low-power, high-capacity data storage devices for classical and quantum computers.

Researchers at the National Institute of Standards and Technology (NIST) in the U.S, the University of Nevada, George Mason University and Japan's National Institute for Materials Science have developed a “quantum ruler” to measure and explore the unique properties of twisted materials like 'magic angle' graphene. 

The work may also lead to a new, miniaturized standard for electrical resistance that could calibrate electronic devices directly on the factory floor, eliminating the need to send them to an off-site standards laboratory.

Researchers from China's Lanzhou University and Japan's Tokyo University of Science have harnessed the surface binding property and redox activity of platinum (Pt)-doped gold (Au) nanoclusters, Au₂₄Pt(PET)₁₈ (PET: phenylethanethiolate, SCH₂CH₂Ph), as a high-efficiency electrocatalyst in lithium–sulfur batteries (LSBs). 

Lithium–sulfur batteries (LSBs) can store three to five times more energy than traditional lithium-ion batteries and so they have emerged as a promising energy storage solution. LSBs use lithium as the anode and sulfur as the cathode, but this combination poses challenges. One significant issue is the “shuttle effect,” in which intermediate lithium polysulfide (LiPS) species formed during cycling migrate between the anode and cathode, resulting in capacity fading, low life cycle, and poor rate performance. Other problems include the expansion of the sulfur cathode during lithium-ion absorption and the formation of insulating lithium–sulfur species and lithium dendrites during battery operation.  While various strategies, such as cathode composites, electrolyte additives, and solid-state electrolytes, have been employed to address these challenges, they usually involve trade-offs and considerations that limit further development of LSBs.

A team of international researchers, led by The University of Hong Kong (HKU) and The University of Science and Technology (HKUST), recently made a discovery in the field of quantum materials, uncovering the controllable nonlinear Hall effect in twisted bilayer graphene. The findings shed new light on the unique properties of two-dimensional quantum moiré materials and hold promise for a wide range of applications in industries such as new materials and quantum information to achieve terahertz detection with ultra-high sensitivity at room temperature.

The team conducted in-depth research using a combination of theory, computation, and experiments. They discovered that by adjusting the dispersion of the topological flat bands in twisted bilayer graphene, the Berry curvature dipole moments, which play a crucial role in the Hall effect can be easily controlled and manipulated.

Researchers from the University of California San Diego and the University of Southern Mississippi recently designed a graphene-enhanced structural supercapacitor. Structural supercapacitors hold promise to expand the energy capacity of a system by integrating load-bearing and energy-storage functions in a multifunctional structure, resulting in weight savings and safety improvements. 

As a proof of concept, the researchers used their structural supercapacitor to build a miniature solar-powered boat. The supercapacitor was molded to form the boat’s hull and then fitted with a small motor and circuit. The circuit was connected to a solar cell. When exposed to sunlight, the solar cell charges the supercapacitor, which in turn powers the boat’s motor. In tests, the boat was able to cruise across the water, demonstrating the efficacy of this innovative energy storage solution.