IBM researchers developed a new process that can be used to fabricate single-oriented, single-layer graphene at wafer-scale. The process uses two exfoliation stages, and the researchers managed to made graphene wafers 4" in size. The researchers believe that in the future graphene will replace silicon as a transistor technology (they quote Nature's estimate of 2021) - and graphene based transistors will achieve speeds of 1 Thz over the next decade.

This process uses the idea that every element in the periodic table has a different adhesion (atomic binding energy) to graphene. They start by growing graphene on a silicon carbide (SiC) substrate, and then separate the graphene from the SiC by using a stressed nickel layer. Then they perform a second exfoliation that removes any graphene in excess of a single-layer by using a thin gold layer thus leaving only single-layer, single-oriented graphene.

Today two different teams of researchers released articles describing new advances in graphene-on-silicon based photodetectors. These devices hold promise because it could lead to more simple device fabrication - and those devices will be very fast compared to current photo detectors and be responsive to a wider range of light frequencies.

But basic graphene photodetectors suffer from low responsivity as graphene will only convert about 2% of the light passing through it to electrical current. This is a high value for an atom-thick material, but it's not enough for a real photodetector.

The wall street journal posted an interesting article and video on graphene. The article discusses the current state of research and business, possible graphene applications and the rush to patent related technologies.

The article starts with the Cambridge graphene research center and then discusses several companies and their graphene programs, including IBM, Nokia, BlueStone Global Tech, Vorbeck Materials, Lockheed Martin and Aixtron.

IBM researchers have developed a graphene-based infrared detector, driven by intrinsic plasmons. This new design proved to be much more photo-responsive compared to non-plasmonic graphene detectors.

The researchers used CVD to grow graphene on copper foil. The copper was etched away and the graphene sheet was transferred to a silicon/silicon-oxide chip. The researchers patterned graphene ribbons (widths of 80 to 200 nm).

Researchers from IBM are studying how plasmons lose their energy in graphene. It turns out that plasmons lose their energy very slowly in graphene, which is good for photonics and quantum optics applications (the longer the plasmons last, the better).

The IBM researchers are using graphene nanoribbons, dots and nanodisk arrays grown on all sorts of substrates (silicon wafers, diamond-like carbon and SiO2, to name just a few). The researchers are using a new technique (based on Fourier transform IR spectrometer) to measure exact plasmon damping mechanisms and rates. Their most important finding is that the graphene plasmons appear to interact strongly with the vibrations of the silicon dioxide substrate surface atoms on which the graphene is deposited. This leads to so-called energy-dependent hybrid plasmon-phonon modes that disperse and decay very differently compared with those modes where graphene is deposited on non-planar diamond-like substrates.

UK patent consultancy CambridgeIP researched graphene patents and they say that the UK may be falling behind in the graphene race. CambridgeIP identified 7,351 graphene patents (and patent applications), and the leading countries by graphene patents are china (2,204), US (1,754) and Korea (1,160). The UK has only 54 graphene patent applications. Back in February the UK government announced a £50 million graphene drive, which aims to bring the country back to the forefront of graphene research.

The leading research institutes (by patents) are Sungkyunkwan University (Korea, 134), Zhejiang University (China, 97), Tsinghua University (China, 92), Rice University (US, 56), MIT (US, 34) and finally Manchester University (16).

Researchers from IBM and University of California Riverside managed to make the slimmest graphene nanoribbon (GNR) ever - just 10 nm in width. Making one is virtually impossible, and the team created a large number of GNRs in parallel. The researchers say that the arrays cover about 50% of the prototype device channel area, which means that integrated circuits based on GNRs with the required high current densities are now possible. The narrow GNRs have a bandgap of about 0.2 eV.

The process the researchers used consists of two main steps: a top-down e-beam lithography step and a bottom-up self-assembly step involving a block copolymer template comprising alternating lamellae of the polymers PS and PMMA.

A research team from IBM Research in Zurich helped to create the smallest Olympic logo ever - made from five carbon rings in graphene:

They call the molecule Olympicene, the smallest molecule containing five carbon rings. The actual molecule was was synthesized at the University of Warwick, after the project was suggested by the Royal Society of Chemistry’s vice president Antony Williams. The work was done by Anish Mistry, a student working with PhD student Ben Moreton.

IBM researchers managed to develop a graphene insulator superlattice that achieves a Teraherz frequency notch filter and a linear polarizer. These kinds of devices can be used in mid- and far-infrared photonic devices, including detectors, modulators and three-dimensional metamaterials. Terhertz is interesting because this kind of frequencies can penetrate paper, wood and other solid objects.

IBM managed to create these devices by using a multi-layer graphene/instulator superlattice and a multi-layer stack structure in microdisk arrays.

IBM has managed to produce RF integrated circuits on an 8" graphene wafer. IBM says that this demonstration is a "major step in transitioning this promising material from a scientific curiosity into a real technology". The graphene was grown on copper foil from high-temperature vapor and later coated with the polymer PMMA.

These are RF devices - as it's still difficult to create logic using graphene (it has no natural bandgap), although some researchers are working towards methods to fix this issue.