2D materials | Graphene-Info

Researchers discover new states of matter that arise from stacking 2D layers of graphene

Researchers from Brown and Columbia Universities in the U.S have demonstrated that unknown states of matter arise from stacking two-dimensional layers of graphene together. These new states have been named the fractional quantum Hall effect (FQHE), and are created through the complex interactions of electrons within and across graphene layers.

"In terms of materials engineering, this work shows that these layered systems could be viable in creating new types of electronic devices that take advantage of these new quantum Hall states," said Jia Li, assistant professor at Brown. Li added: "The findings show that stacking 2-D materials together in close proximity generates entirely new physics."

Read the full story Posted: Jul 04, 2019

Researchers demonstrate fast, non-contact, wafer-scale, atomic layer resolved imaging of 2D materials by Ellipsometric Contrast Micrography

Spectroscopic Imaging Ellipsometry (SIE) is a powerful tool to characterize, analyze and investigate thicknesses, optical properties and defects or impurities of 2D-materials. Recently, researchers from the University of Cambridge, Accurion and the University of Applied Sciences and Arts in Göttingen Germany focused on ellipsometric contrast micrography (ECM), a fast intensity mode within spectroscopic imaging ellipsometry, and showed that it can be effectively used for noncontact, large area characterization of 2D materials like graphene to map coverage, layer number, defects and contamination.

ECM approach image

The team has shown that imaging ellipsometry - in the mode of recording contrast micrographs - can be used to identify, test the quality and quantify 2D materials independently of the substrate and the material. Examples are graphene layers on Si with native oxide or directly on rough Cu catalyst foils as well as mono-layer hexagonal BN .

Read the full story Posted: Aug 22, 2018

Schwarzite carbon structures identified

University of California, Berkeley, researchers have found that three carbon structures recently created by scientists in South Korea and Japan are in fact schwarzites, an elusive carbon structure which researchers predict will have unique electrical and storage properties like those of carbon nanotubes and graphene.

Schwarzites: Long-sought carbon structure joins graphene, fullerene family image

The new structures were built inside the pores of zeolites, crystalline forms of silicon dioxide—sand—more commonly used as water softeners in laundry detergents and to catalytically crack petroleum into gasoline. Called zeolite-templated carbons (ZTC), the structures were being investigated for possible interesting properties, though the creators were unaware of their identity as schwarzites, which theoretical chemists have worked on for decades.

Read the full story Posted: Aug 17, 2018

Carbon nanotubes help create reinforced graphene "rebar"

Rice University researchers have found that fracture-resistant “rebar graphene” is more than twice as tough as pristine graphene. While on the two-dimensional scale, graphene is stronger than steel, its extremely thin nature makes it subject to ripping and tearing. Rebar graphene is the nanoscale analog of rebar (reinforcement bars) in concrete, in which embedded steel bars enhance the material’s strength and durability. Rebar graphene, developed by the Rice lab of chemist James Tour in 2014, uses carbon nanotubes for reinforcement.

In a new study, Rice materials scientist Jun Lou, graduate student and lead author Emily Hacopian and collaborators, including Prof. James Tour, stress-tested rebar graphene and found that nanotube rebar diverted and bridged cracks that would otherwise propagate in unreinforced graphene.

Read the full story Posted: Aug 07, 2018

Paragraf closes second tranche of seed funding round

Paragraf, a Cambridge University graphene spin-out that focuses on the production of graphene and other 2D materials and the development of devices based on these materials, has announced the closure of a second tranche ‎within its seed funding round.

In September 2017, Paragraf closed a £2.64 million seed round to support the development of its first major products. The round was led by Cambridge Enterprise, the commercialization arm of the University of Cambridge, with the participation of Parkwalk Advisors, Amadeus Capital Partners, IQ Capital Partners, Martlet, the investment arm of Marshall of Cambridge Group, and a small group of angel investors. Now, a second tranche was closed, raising an additional sum of £260,000.

Read the full story Posted: May 02, 2018