Graphene: one atom thick material with exciting potential!

Professors from the University of South Florida has found a way to make circuits out of Graphene - using tiny nanoscale defects. They made strips of broken atomic rings in the Graphene, and these have metallic properties - they can act like tiny 'wires'.

Via Engadget

IBM Research demoed a 10 Gbit/sec optical link that has a Graphene photodetector (fabricated on a silicon-on-insulator substrate).

The vertical-incidence metal-graphene-metal photodetector achieved 6.1 milliamps per watt at the communications wavelength of 1.55 microns, but was shown to be useful over a very wide bandwidth of 300 nanometers to 6 microns, making the graphene optical link a promising candidate not only for communications, but for remote sensing, environmental monitoring and surveillance.

Via EETimes

AIXTRON today announced an order for one Black Magic deposition system from Purdue University’s Birck Nanotechnology Center in West Lafayette, IN, USA. The order is for a 2 inch wafer configuration system for the deposition of carbon nanomaterials and high-k oxides by atomic layer deposition (ALD). The order was received in the fourth quarter of 2009 and the system will be delivered in the second quarter of 2010.

Associate Professor Peide Ye of Purdue University comments, “The Black Magic CVD/PECVD platform is vital to our ongoing advanced CMOS device characterization research projects. This first-of-a-kind dual-configuration CVD system will allow us to not only to carry out CNT and graphene deposition but also to prepare high-k oxides by ALD in-situ. Having this unique capability at Birck means that we will be able to optimise carbon/oxide-based materials for the next-generation device channels. The advantage of preparing the oxide in-situ directly after channel growth is that it potentially eliminates contamination and trapped charge, leading to cleaner channel/oxide interfaces and better device performance.”

Researchers from the Rensselaer Polytechnic Institute got a $1 Million grant for a three-year study on a new coating (based on Graphene) for nanosensors that can be used for Oil or Gas exploration. The grant was given by the Advanced Energy Consortium.

Koratkar and colleagues are investigating how the flow of water, steam, or certain gasses over surfaces coated with carbon nanotubes or graphene can generate small amounts of electricity. The researchers seek to explain this phenomenon — which has been observed but is not yet fully understood — and use their findings to create tiny self-powered devices that travel through naturally occurring cracks deep in the earth and can help uncover hidden pockets of oil and natural gas.

Via Rensselaer

Researchers from Cambridge (UK) and CNRS (France) have developed an ultra-fast mode-locked laser using Graphene. Graphene based lasers can be easier and cheaper to make than semiconductor saturable absorber mirrors (SESAMs) based lasers, and will be less limited in their bandwidth.

Graphene ultra-fast laser

The team studied how light is absorbed in graphene and how photo-excited charge carriers behave in the material. In particular, they highlighted the key role of "Pauli blocking" in saturating the light absorption. Because of the Pauli exclusion principle, when pumping of electrons in the excited state is quicker than the rate at which they relax, the absorption saturates. This is because no more electrons can be excited until there is "space" available for them in the excited state.

Since the Dirac electrons in graphene linearly disperse, this means that it is the most wideband saturable light absorber ever, far out-passing the bandwidth provided by any other known material.

The team is now in the process of optimizing a fully functioning wideband tunable laser based on graphene, as well as trying similar experiments with graphene oxide.

Via optics.org

A new research in the National Institute of Standards and Technology (NIST) and the university of Pennsylvania is working towards a Graphene based structure that can be promising for capturing hydrogen. Graphene is not really suited to store hydrogen, but if you stack oxidized Graphene sheets (in a Graphene-Oxide-Framework, or GOF) than it can hold hydrogen in higher quantities. The team says that GOFs can store at least a hundred times more hydrogen than ordinary Graphene Oxide. This can potentially be very useful for fuel-cells or other applications.

Via AZoNano

Osaka's university has a Spintronics research group that is working towards MRAM and STT-RAM using several materials including Graphene. Here's a nice intro video about the group: