New twist on graphene to boost optoelectronics

Researchers at University of California Berkeley, Washington University in St. Louis and Lawrence Berkeley National Laboratory have stacked two sheets of graphene on top of each other and twisted them, which resulted in the conversion of a common linear material into one with nonlinear optical capabilities. This could prove useful for various everyday technologies — from spectroscopy and material analysis to communications and computing.

In the study of optics, scientists distinguish between linear and nonlinear materials. Most materials, including sheets of graphene, are linear. If you shine red light at a sheet of graphene, the photons will either be absorbed or scattered, but in any case - they will remain red.

Talga Resources fast-tracks graphene-enhanced silicon anode product

Talga Resources logo 2017Talga Resources has provided an update on the commercial progress of its graphene-enhanced silicon anode lithium-ion battery product Talnode-Si. Following encouraging early test results, further technical and commercial development of Talnode-Si has been underway at Talga’s facilities in Europe.

Results from this latest phase of development reportedly show continued success of Talga’s silicon anode approach which uses lower-cost metallurgical-grade silicon for a high-energy density anode with mass-producibility potential.

Research team develops new method to generate precisely controlled graphene microbubbles

Researchers at Swinburne University of Technology recently teamed up with teams from National University of Singapore, Rutgers University, University of Melbourne, and Monash University, to develop a method to generate precisely controlled graphene microbubbles on a glass surface using laser pulses.

Schematic of optical setup for characterizing the GO microbubbles imageSchematic of optical setup for characterizing the GO microbubbles. Image from article

Microbubbles - around 1-50 micrometers in diameter - can have various applications like drug delivery, membrane cleaning, biofilm control, and water treatment. They've been applied as actuators in lab-on-a-chip devices for microfluidic mixing, ink-jet printing, and logic circuitry, and in photonics lithography and optical resonators. They also have great potential for other biomedical imaging and applications like DNA trapping and manipulation applications.

University of Washington team finds that carefully constructed stacks of graphene can exhibit highly correlated electron properties

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.

Chalmers team designs method for fabricating atomically sharp nanostructures

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.

Etching hexagonal nanostructures in TMD materials imageProcess 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.