Unique device that combines graphene and boron nitride can switch from superconducting to insulating

Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have designed a graphene device that switches from a superconducting material to an insulator and back again to a superconductor — all with a flip of a switch. The team shared that the device exhibits this unique versatility while being thinner than a human hair.

Graphene and hBN device moves from insulating to superconducting imageViews of the trilayer graphene/boron nitride heterostructure device as seen through an optical microscope. The gold, nanofabricated electric contacts are shown in yellow; the silicon dioxide/silicon substrate is shown in brown and the boron nitride flakes

"Usually, when someone wants to study how electrons interact with each other in a superconducting quantum phase versus an insulating phase, they would need to look at different materials. With our system, you can study both the superconductivity phase and the insulating phase in one place," said Guorui Chen, the study's lead author and a postdoctoral researcher in the lab of Feng Wang, who led the study. Wang, a faculty scientist in Berkeley Lab's Materials Sciences Division, is also a UC Berkeley physics professor.

Graphene Flagship partners launch rocket to test the possibilities of printing graphene inks in space

Graphene Flagship partners, Université Libre de Bruxelles, University of Pisa and the University of Cambridge, in collaboration with the European Space Agency (ESA) and the Swedish Space Corporation (SSC), recently launched The Materials Science Experiment Rocket (MASER) into space. The objective is to test the printing of graphene patterns on silicon substrates in zero gravity conditions.

New graphene experiment launches into space image

The experiment aims to test the possibilities of printing graphene inks in space. Studying the different self-assembly modes of graphene into functional patterns in zero-gravity will enable the fabrication of graphene electronic devices during long-term space missions, as well as help understand fundamental properties of graphene printing on Earth. This mission is also a first step towards the investigation of graphene for radiation shielding purposes, an essential requirement of manned space exploration.

Laser technique that opens a bandgap in graphene could allow for next-gen graphene electronics

Researchers from Purdue University, the University of Michigan and the Huazhong University of Science and Technology have used a technique called "laser shock imprinting" to permanently stress graphene into having a band gap, which could mean it would be possible to use it in various electronic components.

The researchers used a laser to create shock wave impulses that penetrated an underlying sheet of graphene. The laser shock stretches the graphene onto a permanent, trench-like mold. This caused the widening of band gap in graphene to a record 2.1 electronvolts. Previously, scientists achieved 0.5 electronvolts, barely reaching the benchmark to make graphene a semiconductor like silicon.

Researchers bind hydrogen to graphene in a super-fast reaction that also opens up a bandgap

Researchers from Göttingen and Pasadena (USA) have produced an "atomic scale movie" showing how hydrogen atoms chemically bind to graphene in one of the fastest reactions ever studied. The team found that by adhering hydrogen atoms to graphene, a bandgap can be formed.

Hydrogen binds to graphene in 10 femtoseconds imageThe hydrogen atom (blue) hits the graphene surface (black) and forms a bond with a carbon atom (red). The high energy of the hydrogen atom is first absorbed by neighboring carbon atoms (orange and yellow) and then passed on to the graphene as a sound wave

The research team bombarded graphene with hydrogen atoms. "The hydrogen atom behaved quite differently than we expected," says Alec Wodtke, head of the Department of Dynamics at Surfaces at the Max Planck Institute (MPI) for Biophysical Chemistry and professor at the Institute of Physical Chemistry at the University of Göttingen. "Instead of immediately flying away, the hydrogen atoms 'stick' briefly to the carbon atoms and then bounce off the surface. They form a transient chemical bond," Wodtke exclaims. Something else also surprised the scientists: The hydrogen atoms have a lot of energy before they hit the graphene, but not much left when they fly away. It seems that hydrogen atoms lose most of their energy on collision, but where it goes remained to be examined.

Canada-based University of Guelph to receive grant for graphene research

A professor at the University of Guelph in Canada is receiving $1.4 million CAD (a little over $1 million USD) over the next seven years toward his research, which includes developing practical graphene applications. Prof. Aichen Chen was recently named as a tier-1 Canada Research Chair in electrochemistry and nanoscience, a title that came with the $1.4 million in funding.

For the past five years, Chen has been working with graphene — aiming to use it to create innovative green technologies for projects like energy storage and clean drinking water.

Versarien - Think you know graphene? Think again! Versarien - Think you know graphene? Think again!