Teams from the University of York and Roma Tre University state that ultra-low-power transistors could be built using composite materials based on single layers of graphene and transition metal dichalcogenides (TMDC). These materials, they note, could be used to achieve a sought-after electrical control over electron spin.
Previously graphene-oxide membranes were shown to be completely impermeable to all solvents except for water. However, a study published in Nature Materials, now shows that we can tailor the molecules that pass through these membranes by simply making them ultrathin.
Liquid-phase exfoliation of nanosheets from bulk materials is generally achieved by high-energy processes like ultrasonication, coupled with chemical treatments to prevent reaggregation. Such methods can be effective and inexpensive, but monolayers usually make up no more than a few per cent of the yield, and residual chemical additives can compromise the properties of the resulting products.
The article reports vertically illuminated, resonant cavity enhanced, graphene–Si Schottky photodetectors (PDs) operating at 1550 nm. These exploit internal photoemission at the graphene–Si interface. To obtain spectral selectivity and enhance responsivity, the PDs are integrated with an optical cavity, resulting in multiple reflections at resonance, and enhanced absorption in graphene. We get a wavelength-dependent photoresponse with external (internal) responsivity ∼20 mA/W (0.25A/W). The spectral selectivity may be further tuned by varying the cavity resonant wavelength. Our devices pave the way for developing high responsivity hybrid graphene–Si free-space illuminated PDs for optical communications, coherence optical tomography, and light-radars.
The influence of (nickel nitrate/citric acid) mole ratio on the formation of sol-gel end products was examined. The formed Ni/NiO nanoparticle was anchored on to reduced graphene-oxide (rGO) by means of probe sonication.
Lamborghini and MIT have announced a collaboration on a 3-year project to develop a graphene-enhanced supercapacitor electric vehicle. The Lamborghini-MIT partnership could, however, end up being extended as there is no target date for the car’s completion.
Due to its excellent properties, graphene is set to make an impact across a wide range of industries. Scalable production is one of the most important challenges. At Graphene Week in Athens, scientists from the European project Gladiator presented a new technique to monitor the growth of graphene, aiming to improve the quality and reduce the fabrication costs.
Graphene can be used to make car seats and aircraft antenna protection enclosures lighter, which will reduce fuel consumption. These are just two examples of the uses of this material exhibited during Graphene Week in Athens, where companies and research centres presented their latest results.
In new work, reported in ACS Applied Materials & Services (“Controlling Water Intercalation Is Key to a Direct Graphene Transfer”), researchers in Belgium demonstrate that interfacial water can insert between graphene and its growth substrate despite the hydrophobic behavior of graphene.
In their paper, the researchers discuss in detail graphene delamination from platinum (Pt) surfaces using electrochemical methods. They show that water intercalation between graphene and a Pt surface is critical to achieve a successful graphene delamination using an electrochemical method.
We talk a lot about graphene and why it promises to be a wonder material, but how do you actually make it?