Graphene is a 2-dimensional layer of tightly bound carbon atoms arranged in hexagonal arrays. Sheets of graphene are the building blocks of graphite. Due to its phenomenal electronic properties, graphene has been considered as a leading material for next generation electronic devices in the multibillion dollar semiconductor industry.
Using a process called silicon sublimation, EOC researchers David Snyder and Randy Cavalero thermally processed silicon carbide wafers in a physical vapor transport furnace until the silicon migrated away from the surface, leaving behind a layer of carbon that formed into a one- to two-atom-thick film of graphene on the wafer surface. Achieving 100mm graphene wafers has put the Penn State EOC in a leading position for the synthesis of ultra-large graphene and graphene-based devices.
With the support of the Naval Surface Warfare Center, EOC researchers are initially focusing on graphene materials to improve the transistor performance in various radio frequency (RF) applications. According to EOC materials scientist Joshua Robinson, Penn State is developing graphene device processing to enhance graphene transistor performance and has fabricated RF field effect transistors on 100mm graphene wafers.
Another goal of the Penn State researchers is to improve the electron mobility of the Si-sublimated wafers to nearer the theoretical limit, approximately 100 times faster than silicon. That will require improvements in the material quality and device design, says Robinson, but there is significant room for improvements in growth and processing, he believes.
In addition to silicon sublimation, EOC researchers Joshua Robinson, Mark Fanton, Brian Weiland, Kathleen Trumbull, and Michael LaBella are developing the synthesis and device fabrication of graphene on silicon using a non-sublimation route as a means to achieve wafer diameters exceeding 200mm, a necessity for integrating graphene into the existing semiconductor industry. Graphene has the potential to enable terahertz computing at processor speeds 100 to 1000 times faster than silicon.
First discovered in 2004, graphene is now being studied worldwide for electronics, displays, solar cells, sensors, and hydrogen storage. With its remarkable physical, chemical, and structural properties, graphene promises to become a key material for 21st century technology.
The Materials Research Institute coordinates the research of more than 200 materials scientists at Penn State. The Millennium Science Complex, now under construction, is a $225M facility for materials and life sciences research scheduled to open at University Park in summer 2011. Visit MRI on the Web at www.mri.psu.edu.
EOC Contact: Joshua Robinson, Ph.D., firstname.lastname@example.org
Joshua Robinson | Newswise Science News
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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