Electronics - Page 30

Scientists at the University of Kansas managed to fabricate an innovative substance made of an atomic sheet of graphene interlocked with a sheet tungsten disulfide that could be used for solar cells and flexible electronics.

The material was formed using "layer to layer assembly" as a versatile bottom-up nanofabrication technique. The scientists then examined the motion of electrons between the layers through ultrafast laser spectroscopy, and found that nearly 100% of the electrons that absorbed energy from the laser pulse moved from the tungsten layer to the graphene within one picosecond, proving that the new material combines the properties of each component layer.

Researchers at the University of Manchester developed a new coating made from graphene-oxide that can be used to enable ultra-strong non-corrosive coating paints, hermetic food packaging and even a good substrate for flexible electronics.

The researchers developed the graphene-oxide coating by taking graphene-oxide and treating it with a "simple chemical treatment". The resulting film behaves like graphite in terms of chemical and thermal stability but becomes mechanically nearly as tough as graphene.

Researchers from the University of Texas at Austin, in collaboration with Aixtron developed a new method to grow high-quality wafer-scale (300 mm) graphene sheets. This process may enable the integration of graphene with Silicon CMOS and pave the way towards graphene-based electronics.

The method is based on CVD growth on polycrystalline copper film coated silicon substrates. They report that their graphene has better charge carrier transport characteristics compared to previously synthesized poly- or single-crystalline wafers. The graphene has few defects and covers over 96% of the 300-mm wafer substrate.

The University of Surrey in the UK is establishing a graphene center, within its Advanced Technology Institute (ATI). The Institute will extend its research into the uses and manufacture of graphene across such applications as high frequency electronics, flexible and transparent electronics, smart coatings and interconnect technology. The university is also interested in using graphene in solar cells, supercacitors, printed transistors and OLED displays.

The ATI developed Photo Thermal deposition technology that can deposit electronic grade graphene on wafer scale substrates. The tool performs catalyst deposition and graphene growth, allowing high volume production. The graphene center received more than £1.2 million (over $2 million) from the EPSRC, NPL and a range of industrial companies. Academic partners in the new center include the Universities of Cambridge, Oxford, Manchester, Imperial, Exeter, Trinity College Dublin and Aristotle University of Thessaloniki.

Researchers are developing flash memory devices that store the charge in nanocrystals instead of the usually used polysilicon layers. These kinds of devices are less sensitive to local defects and offer high-density memory potential.

Researchers from Samsung Electronics (and Korea's Kyung Hee University) are now developing similar flash devices based on graphene quantum dots (GQDs). The performance of such a device is promising, with an electron density that is comparable to semiconductor and metal nanocrystal based memories. Those flash memory can also be made flexible and transparent.

Researchers from the University of Manchester demonstrated that when growing graphene on a hexagonal substrate (hBN, or hexagonal Boron-Nitride, in that case), small changes in the crystal structure can open a band-gap in the graphene. The researchers also demonstrated that a graphene grown on the hBN can exist in an alternative structure in which the band gap is much smaller.

The lattice structure of hBN (also called white graphene) is quite similar to graphene. When you place the graphene on top of the hBN, a moiré superlattice is created. The periodic potential associated with this superlattice causes a number of new and interesting electronic phenomena to occur in graphene, including Hofstadter's butterfly, which has been shown before.

Researchers from the University of Arizona discovered how to change the crystal structure of graphene with an electric field. This unique technique may enable graphene transistors - and electronics and microprocessors applications.

The researchers used trilayer graphene, in which the top layer can be placed in two different ways - either the atoms are placed on the atoms of the bottom layer or with a slight offset (so the atoms are placed on the space between the bottom layer atoms). In a tri-layer graphene sheet, this happens naturally and actually the two stacking configurations exist together with a sharp boundary between them.

Samsung announced that they developed a breakthrough large-area graphene synthesis process. The company says this is one of the most significant breakthroughs in graphene research ever, and they expect this new technique to accelerate graphene commercialization towards applications in electronics.

This process was discovered by researchers at Samsung's Advanced Institute of Technology (SAIT) in collaboration with Sungkyunkwan University. The process can be used to grow single crystal graphene on the current semiconductor wafer scale while maintaining graphene's electric and mechanical properties.

Researchers from the University of Nebraska-Lincoln developed a chemical process to produce graphene nanoribbons (GNRs). This bottom-up method can be used to produce very narrow GNRs (2 nanometers wide). The researchers say it is easy to scale up their process.

The team is now testing their ribbons for applications in electronics, gas sensors and solar cells. The electronic properties of their GNRs can be tuned by changing the synthetic conditions.

Intel's CEO Brian Krzanic participated in Reddit's Ask Me Anything (AMA) session. One of the questions was "how does the development of Graphene change the game for Intel?"

Here's Brian's answer: "Graphene, carbon nano tubes.. and other 3-5 materials will become very important to semiconductors over the next few years... they will allow us to lower leakage and power while reducing geometries."