graphene tagged posts

Researchers have made the first important step toward integrating atomically precise graphene nanoribbons (APGNRs) onto nonmetallic substrates. Credit: Adrian Radocea, Beckman Institute for Advanced Science and Technology

Researchers have demonstrated the first important step toward integrating atomically precise graphene nanoribbons (APGNRs) onto nonmetallic substrates. Silicon crystals are the semiconductors most commonly used to make transistors, which are critical electronic components used to carry out logic operations in computing. However, as faster and more powerful processors are created, silicon has reached a performance limit: the faster it conducts electricity, the hotter it gets, leading to overheating.

Graphene, made of a single-atom-thick sheet of carbon, stays much cooler a...

Simulations by Rice University scientists show that placing cones between graphene and carbon nanotubes could enhance heat dissipation from nano-electronics. The nano-chimneys become better at conducting heat-carrying phonons by spreading out the number of heptagons required by the graphene-to-nanotube transition. Credit: Alex Kutana/Rice University

Scientists calculate tweaks to graphene would form phonon-friendly cones. A few nanoscale adjustments may be all that is required to make graphene-nanotube junctions excel at transferring heat. The Rice lab of theoretical physicist Boris Yakobson found that putting a cone-like “chimney” between the graphene and nanotube all but eliminates a barrier that blocks heat from escaping...

Combining graphene, its sister material boron nitride and a nanoscale gold grating to create a new class of optical modulator. Credit: University of Manchester

Scientists at The University of Manchester have discovered a new method of creating optoelectronic circuits using graphene and other 2D material much smaller than their current counterparts. Optoelectronics, the technology that uses pulses of light rather than traditional electrical signals, is vital for telecommunication networks.
Modulators are important in optoelectronic circuits as they control the signals passed through optoelectronic devices. Previous attempts to create hybrid modulators incorporating graphene have yielded promising although limited results.

Writing in Nature Communications, researchers led by Professor Sasha ...

An illustration of refraction through a normal optical medium versus what it would look like for a medium capable of negative refraction. —Photo courtesy of Cory Dean

Engineers have directly observed for the first time negative refraction for electrons passing across a boundary between 2 regions in a conducting material. First predicted in 2007, this effect has been difficult to confirm experimentally. The electrons in the atomically thin material behave like light rays, which can be manipulated by such optical devices as lenses and prisms. The findings could lead to the development of new types of electron switches, based on principles of optics rather than electronics.

“The ability to manipulate electrons in a conducting material like light rays opens up entirely new ways of thinking a...