This tells us that full blown graphene fabrication and manufacturingintegration is well on the way to achieving it's natural promise. Yetit is barely into public awareness even several years after itarrived on the scene.
I also think that manufacturing is barely beginning to master thisproduct and expect to see astonishing things here not possible onanything else.
We can see decades of advances coming into this easily equal to whatwas experienced with silicon.
Flexible graphenetransistor sets new records
Dec 10, 2012
http://physicsworld.com/cws/article/news/2012/dec/10/flexible-graphene-transistor-sets-new-records
Researchers at theUniversity of Texas at Austin in the US say that they have madestate-of-the-art flexible graphene field-effect transistors withrecord current densities and the highest power and conversion gainever. The transistors also show near-symmetric electron and holetransport, are the most mechanically robust flexible graphene devicesfabricated to date, and can be immersed in a liquid without any illeffects.
Graphene is a single,flat sheet of carbon arranged in a honeycombed lattice. It has manyunique electronic and mechanical properties, such as extremely highcarrier mobility – which means that it is an ideal material for usein ultrafast transistors. The material can also absorb light over arange of wavelengths in the electromagnetic spectrum from the visibleto mid-infrared and is highly transparent to light. The fact that itis mechanically flexible while being incredibly strong is good newstoo.
The researchers, ledby Deji Akinwande and Rodney Ruoff, made their graphene field-effecttransistors (GFETs) directly atop patterned dielectrics on plasticsheets using conventional microelectronic lithography. The deviceshave a unique structure, explains Akinwande, in which multi-fingermetal gate electrodes are embedded in the plastic sheet. They arealso made using graphene that has been grown by chemical vapourdeposition (CVD), which can now produce as good graphene flakes ascan be obtained by exfoliation (the famous "sticky-tape"method).
Record properties
The innovativeproduction technique means that graphene can easily be integrated andfabricated on plastic sheets that have been pre-patterned with metalgates. This produces transistors in which charge carriers can moveextremely fast and in which electrons and holes move in the same way.The devices are also extremely compliant and can accommodatemechanical strains of up to 9% and can be bent and unbent over formore 20 continuous cycles – a record number for flexibleGFETs.
"Overall, ourtransistors feature record circuit performance, the largestmechanical bending and the highest extrinsic cut-off frequencies (ofabout 2.23 GHz) to date for any graphene flexible nanoelectronicdevice," says Akinwande. "What is more, the devices areliquid-resistant thanks to the fact that the surface of the grapheneis passivated with silicon nitride and the plastic substrate isself-passivated. In short, we found that they could beaccidentally dropped into everyday liquids, such as milk, tea orcoffee, and can even survive being run over by a moving vehicle –all without suffering damage to their outstanding properties."
Smart applications
The extremelyflexible, high-performance devices could be ideal for smart,conformal, advanced electronics that could offer performancecapabilities beyond today’s silicon-based technology while alsobeing cheaper, lighter, more environmentally friendly and witharbitrary form factors, claims Akiwande. "Potential applicationsinclude flexible smartphones, displays, fabric and even smart walls,"he adds.
The team, which ispresenting its work this week at the International Electron DevicesMeeting in San Francisco, is now busy trying to make flexiblewireless radios and mobile systems using the new GFETs at gigahertzfrequencies. "From a basic research point of view, we are alsolooking into heat management in these devices on flexible plasticsubstrates, which is a major issue for transistors operating at highspeeds and current densities," adds Akinwande.
About the author
Belle Dumé is acontributing editor to nanotechweb.org
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