July 2012

Researchers from Germany and Sweden developed high-performance monolithic graphene transistors using a simple lithographic etching process. The process involves heating silicon carbide, removing the silicon atoms (which leaves a single graphene sheet). A lithographic mask is laid down, and reactive ion etching is used to define the transistors. Hydrogen gas was introduced during the growth of the middle graphene channel, turning it from contact (source/drain) graphene into gate graphene.;

In the current process, each transistor is about 100 micrometers across, so they cannot tell how fast this transistor will be in small scale. Currently the performance corresponds well with textbook predictions for the cutoff frequency of a metal-semiconductor field-effect transistor. They say that some "very simple changes" could increase performance by about 30.

Graphene Laboratories is growing quickly - and the company has expanded its production facilities and staff. The company has added additional space in the Stony Brook Incubator in Calverton, New York, with the space being used to host a new Chemical Vapor Deposition furnace for graphene growth. The staff has grown to over 10 employees (including four interns).

Graphene Labs told us that their highest selling products are silicon dioxide wafers with graphene sheets on them and graphene coatings (for applications such as ITO replacement and in electronic components). Another popular product is the company's 3D graphene foam materials, which because of their high surface area have potential applications in chemical sensing and energy storage.

The National Physical Laboratoy in Middlesex, UK is hosting a graphene conference titled "Graphene: From Research to Applications" (October 15-16, 2012). The conference will review some of the new concepts in graphene electronics, physics, technology and metrology. Several academia and industry experts will give talks.

An artificial photosynthesis system converts sunlight into chemical energy (as opposed to a PV/solar system which produces electricity). Such a system could be used to produce renewable fuels - but developing an efficient system is very challenging. Now researchers form the Korea Research Institute of Chemical Technology and the Ewha Womans University in Seoul have discovered that a graphene-based photocatalysis could improve the efficiency of such a system.

The researchers coupled graphene to a porphyrin enzyme. The resulting material converts sunlight and carbon dioxide into formic acid. This material is highly functional in the visible light spectrum, and its overall efficiency is significantly higher than the efficiency of other photocatalysts.

mPhase Technologies and the Stevens Institute of Technology will collaborate on the design and fabrication of a new battery technology that combines mPhase's Smart NanoBattery Technology with Stevens' graphene-based inkjet printing method for printing electrodes and electronic circuits. mPhase and Stevens will also "explore" the possibility of funding Stevens' graphene research activities.

Back in March mPhase announced they are exploring the printing of its "Smart NanoBattery" using graphene (and possibly other advanced materials), so it's good to know they have now found an R&D partner.

Researchers from Columbia and Singapore discovered that graphene has a remarkable optical nonlinear behavior - which could lead to ultra low power photonic integrated circuits. The researchers managed to use a single sheet of graphene and silicon to generate microwave photonic signals and perform parametric wavelength conversion at telecommunication wavelengths.

The researchers say that by optically driving the electronic and thermal response in the hybrid silicon-graphene chip they could generate a RF carrier on top of the transmitted laser beam and control its modulation with the laser intensity and color. The resonant quality of this cheap is 50 times lower than the best pure-silicon chip.

Konstantin Novoselov from the University of Manchester discovered that if you make a hold in a graphene sheet it automatically "heals" itself back together. This was discovered when the researchers used an electron beam to etched tiny holes in graphene, adding a few palladium or nickel atoms to catalyze the dissociation of carbon bonds and bind to the edges of the holes making them stable.

When they tried adding carbon atoms, they found that these displaced the metal atoms and closed the holes together. The structure of the repaired area depends on carbon structure: hydrocarbon for example contains non-hexagonal defects while pure carbon results in perfect graphene repairs.

Vorbeck Materials plans to purchase a 42,000-square-foot plant in Pocomoke City, Maryland. The state of Maryland will provide incentive-based financing for the building, including deferred payments and interest forgiveness if the company achieves the employment goals of 50 employees within 3 years.

Vorbeck plans to produce its Graphene based inks for the printed electronics market.

Researchers from the University of Arkansas have managed to study and control the transition from graphite to graphene. Normally this transition can be random, but the new technique (called electrostatic manipulation scanning tunneling microscopy) stabilizes the transition and study it.

The new technique uses a moving surface, unlike traditional methods that use a static surface. Using this technique, the researchers can tell how much force it takes to create graphene and how much distance exists between graphene and the graphite as well as to track the total energy of the process.