Graphenea, Nokia and IEMN-CNRS collaborate to create high-frequency graphene transistors on flexible substrates

Scientists from IEMN-CNRS, Graphenea, and Nokia have demonstrated flexible graphene transistors with a record high cut-off frequency of 39 GHz. The graphene devices, made on flexible polymer substrates, are stable against bending and fatigue of repeated flexing.

The graphene field effect transistor (GFET) is made from high quality CVD grown graphene with a carrier mobility of ~2500 cm2 V-1 s-1 on a flexible Kapton substrate with a thin alumina dielectric spacer in the channel region. The use of such sophisticated and optimized materials leads to the record high frequency performance as well as stability against bending. The GFET reportedly continues to operate even after 1,000 bending cycles and can be flexed to a radius of 12 mm with a cutoff frequency shift of up to 10%.

Graphene enables ultrahigh sensitivity infrared detectors

Researchers from the Graphene Flagship, working at the University of Cambridge (UK), Emberion (UK), the Institute of Photonic Sciences (ICFO; Spain), Nokia UK, and the University of Ioannina (Greece) have developed a novel graphene-based pyroelectric bolometer - an infrared (IR) detector with record high sensitivity for thermal detection, capable of resolving temperature changes down to a few tens of µK. This work may open the door to high-performance IR imaging and spectroscopy.

Cambridge team develops sensitive IR bolometer

The technology is focused on the detection of the radiation generated by the human body and its conversion into a measurable signal. The key point is that using graphene, the conversion reaches performance more than 250 times better than the best sensor already available. But the high sensitivity of the detector could be of use for spectroscopic applications beyond thermal imaging. With a high-performance graphene-based IR detector that gives a strong signal with less incident radiation, it is possible to isolate different parts of the IR spectrum. This is of key importance in security applications, where different materials – explosives, for instance – can be distinguished by their characteristic IR absorption or transmission spectra.

Nokia graphene updates from the 2016 MWC

The graphene keynote speech in the MWC 2016 included Nokia's Head of Business Line, Tapani Ryhanen's talk on graphene activity in Nokia.

It was a fascinating segment that shed light on the company's graphene-related activities, some of which (as can be seen in the image above) are energy storage applications, sensors, various electronic devices, photonics, optoelectronics and even graphene manufacturing - which shows that the company is really aiming at completing a full circle of graphene use.

Electricity can flow through graphene at high frequencies without energy loss

Researchers at Plymouth University, Cambridge and Tohoku (Japan) Universities and Nokia Technologies have found that electrical signals transmitted at high frequencies through graphene do not lose energy. In fact, the study showed that graphene out-performs any other known material, including superconductors, when carrying high-frequency electrical signals compared to direct current.

This finding may result in wide-ranging technology developments like next generation high-speed transistors, amplifiers, mobile phones, satellite communications and ultra-sensitive biological sensors.