Researchers design method that makes graphene nanoribbons easier to produce

Russian researchers have proposed a new method for synthesizing high-quality graphene nanoribbons. The team's approach to chemical vapor deposition offers a higher yield at a lower cost, compared with the currently used nanoribbon self-assembly on noble metal substrates.

Two nanoribbon edge configurations imageTwo nanoribbon edge configurations. The pink network of carbon atoms is a ribbon with zigzag (Z) edges, and the yellow one has so-called armchair (A) edges. Image credit MIPT

Unlike silicon, graphene does not have the ability to switch between a conductive and a nonconductive state. This defining characteristic of semiconductors is crucial for creating transistors, which are the basis for all of electronics. However, once you cut graphene into narrow ribbons, they gain semiconducting properties, provided that the edges have the right geometry and there are no structural defects. Such nanoribbons have already been used in experimental transistors with reasonably good characteristics, and the material’s elasticity means the devices can be made flexible. While it is technologically challenging to integrate 2D materials with 3D electronics, there are no fundamental reasons why nanoribbons could not replace silicon.

Researchers develop monolayer graphene-based reversible self-folding structures

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.

 Share  Email  Home Nanotechnology Nanophysics Home Nanotechnology Nanomaterials JANUARY 11, 2021 FEATURE  Self‐folding 3-D photosensitive graphene architectures imageMechanism 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.

New graphene hybrid material could open the door to highly efficient supercapacitors

A research team working with Roland Fischer, Professor of Inorganic and Metal-Organic Chemistry at the Technical University Munich (TUM), has developed a highly efficient supercapacitor based on a novel, powerful and sustainable graphene hybrid material that reportedly has comparable performance data to currently utilized batteries.

Powerful Graphene Hybrid Material for Highly Efficient Energy Storage imageGraphene hybrid made from metal organic frameworks (MOF) and graphenic acid make an excellent positive electrode for supercapacitors, which thus achieve an energy density similar to that of nickel-metal hydride batteries. Credit: Prof. Dr. J. Kolleboyina

A common problem with supercapacitors to date was their lack of energy density. While lithium accumulators reach an energy density of up to 265 Kilowatt hours (KW/h), supercapacitors thus far have only been able to deliver a fraction of that. The team working with TUM's Roland Fischer has now developed a novel, powerful as well as sustainable graphene hybrid material for supercapacitors. It serves as the positive electrode in the energy storage device. The researchers are combining it with a proven negative electrode based on titan and carbon.

Researchers design a new graphene/gold platform for terahertz nonlinear photonics

A German-Spanish research team recently developed a material system to generate terahertz pulses much more effectively than before. It is based on graphene, coated with a metallic lamellar structure.

Some time ago, a team of experts working on the HZDR accelerator ELBE were able to show that graphene can act as a frequency multiplier: When it is irradiated with light pulses in the low terahertz frequency range, these are converted to higher frequencies. Until now, the problem has been that extremely strong input signals, which in turn could only be produced by a full-scale particle accelerator, were required to generate such terahertz pulses efficiently."This is obviously impractical for future technical applications," explains the study's primary author Jan-Christoph Deinert of the Institute of Radiation Physics at HZDR. "So, we looked for a material system that also works with a much less violent input, i.e., with lower field strengths."

Sparc launches graphene sensor project to detect human and animal diseases

Sparc Technologies, which recently announced the acquisition of Australian company Graphene Technology Solutions (GTS) as well as its plan to become a “significant developer of graphene-based products that will disrupt and transform industrial markets, has established a new graphene bio-medical division aimed at developing non-invasive graphene-based breath sensing devices for detection of diseases in humans and animals.

Sparc will advance the project together with cornerstone shareholder, strategic partner and leading graphene research centre the University of Adelaide (UA) in order to establish and develop non-invasive sensing devices for human and veterinarian applications.