#Boron Turns Graphene into Blue light Emitter FRANKFURT, Germany, July 14, 2015 Chemists at Goethe University Frankfurt have developed a new class of organic luminescent materials through the targeted introduction of boron
atoms into graphene. The compounds exhibit an intense blue fluorescence and, consequently, are of interest for use as organic LEDS (OLEDS).
Within graphene, benzene rings are fused to form a honeycomb structure. Sections of this structure, referred to as nanographenes or polycyclic aromatic hydrocarbons (PAHS), play an integral role in organic electronics.
Within the study, boron atoms specifically replaced the two meso carbon atoms within the PAH, which resulted in its ability to transform a near-infrared dye into a blue luminophore.
The boron-containing nanographenes have an impact on two key properties of an OLED luminophore
"For a long time, efforts were focused largely on affecting the properties of nanographenes by chemically manipulating their edges,
Hertz and Wagner anticipate that such materials like the graphene flakes they developed will be particularly suitable for use in portable electronic devices,
#Scientists Make Friction Disappear By Coating Diamonds With Graphene Diamonds are already one of the hardest natural substances known to science.
But combine them with graphene, and diamond nanoparticles are also incredibly slippery, which can be useful
Scientists at Argonne National Laboratory recently announced that the combination of tiny bits of diamond with the two-dimensional graphene created tiny structures that had superlubricity--meaning that the friction between them
When the diamond nanoparticles came in contact with the thin sheets of graphene (carbon that's only an atom thick) the graphene rolled up around the diamond nanoparticles,
With the new graphene coating, the diamond particles could roll far more easily over a larger diamond-like surface that the researchers used as a testing ground.
It's specifically the interaction between graphene and diamond that makes the superlubricity possible right now,
including those that are made with graphene electrodes
#Gold Nano-Spirals Could Protect Against Identity Theft Most other investigators who have studied the remarkable properties of microscopic spirals have done so by arranging discrete nanoparticles in a spiral pattern:
#Laser-induced graphene'super'for electronics: Flexible 3-D supercapacitors tested Rice university scientists advanced their recent development of laser-induced graphene (LIG) by producing
and testing stacked, three-dimensional supercapacitors, energy storage devices that are important for portable, flexible electronics. The Rice lab of chemist James Tour discovered last year that firing a laser at an inexpensive polymer burned off other elements and left a film of porous graphene, the much-studied atom-thick
lattice of carbon. The researchers viewed the porous, conductive material as a perfect electrode for supercapacitors or electronic circuits.
An electron microscope image shows the cross section of laser-induced graphene burned into both sides of a polyimide substrate.
since their work to make vertically aligned supercapacitors with laser-induced graphene on both sides of a polymer sheet.
But the graphene retains its ability to move electrons quickly and gives it the quick charge
#Defying the Achilles heel of'wonder material'graphene: Resilience to extreme conditions Researchers from the University of Exeter have discovered that Graphexeter--a material adapted from the'wonder material'graphene--can withstand prolonged exposure to both high temperature and humidity.
The research showed that the material could withstand relative humidity of up to 100 per cent at room temperature for 25 days as well as temperatures of up to 150c--or as high as 620c in vacuum.
The superior stability of Graphexeter as compared to graphene was unexpected since the molecules used to make Graphexeter (that is Fecl3) simply melt in air at room temperature.
At just one atom thick graphene is the thinnest substance capable of conducting electricity. It is very flexible
and engineers to adapt graphene for flexible electronics. This has been a challenge because of its sheet resistance
In 2012 the teams of Dr Craciun and Profesor Russo from the University of Exeter's Centre for Graphene science discovered that sandwiched molecules of ferric chloride between two graphene layers make a whole new system that is the best known transparent
#Researchers use oxides to flip graphene conductivity A team of researchers from the University of Pennsylvania;
By demonstrating a new way to change the amount of electrons that reside in a given region within a piece of graphene they have a proof-of-principle in making the fundamental building blocks of semiconductor devices using the 2-D material.
Moreover their method enables this value to be tuned through the application of an electric field meaning graphene circuit elements made in this way could one day be rewired dynamically without physically altering the device.
Chemically doping graphene to achieve p -and n-type version of the material is possible but it means sacrificing some of its unique electrical properties.
but manufacturing and placing the necessary electrodes negates the advantages graphene's form factor provides.
We've come up with a non-destructive reversible way of doping Rappe said that doesn't involve any physical changes to the graphene.
The team's technique involves depositing a layer of graphene so it rests on but doesn't bond to a second material:
Here we have graphene standing by on the surface of the oxide but not binding to it.
or gaining electrons the graphene says'I can hold the electrons for you and they'll be right nearby.'
Because the lithium niobate domains can dictate the properties Shim said different regions of graphene can take on different character depending on the nature of the domain underneath.
That allows as we have demonstrated a simple means of creating a p-n junction or even an array of p-n junctions on a single flake of graphene.
Such an ability should facilitate advances in graphene that might be analogous to what p-n junctions and complementary circuitry has done for the current state-of-the-art semiconductor electronics.
What's even more exciting are the enabling of optoelectronics using graphene and the possibility of waveguiding lensing and periodically manipulating electrons confined in an atomically thin material.
and the charge carrier density of the graphene suspended over it. And because the oxide polarization can be altered easily the type
and extent of supported graphene doping can be altered along with it. You could come along with a tip that produces a certain electric field
and the graphene's charge density would reflect that change. You could make the graphene over that region p-type
or n-type and if you change your mind you can erase it and start again.
#Graphene quantum dot LEDS Graphene is a 2d carbon nanomaterial with many fascinating properties that can enable to creation of next-generation electronics.
However, it is known that graphene is not applicable to optical devices due to its lack of an electronic band gap.
On the other hand, graphene quantum dots (GQDS), which are merely a few nanometers large in the lateral dimension, are shown to emit light upon excitation in the visible spectral range.
Seunghyup Yoo (Electrical engineering) have succeeded in developing LEDS based on graphene quantum dots. Highly pure GQDS were synthesized by an environmentally-friendly method designed by Prof.
The three-part structures consist of a base of graphene followed by atomic layers of either molybdenum disulfide (Mos2
#Graphene: Magnetic sensor 100 times more sensitive than silicon equivalent Scientists have created a graphene-based magnetic sensor 100 times more sensitive than an equivalent device based on silicon.
Bosch has long been involved in sensor technology, notably in the automotive sector. In 2008, the company expanded beyond its pressure, acceleration and gyroscopic motion sensors, to geomagnetic, temperature, humidity,
Interested in whether graphene could enable new applications and improved sensor performance, Bosch has been investigating the use of the two-dimensional material in its pressure,
Top-down approaches to graphene device fabrication such as mechanical and chemical exfoliation would not work on a commercial scale,
Roelver cautioned that graphene-based sensor applications will require 5-10 years before they can compete with established technologies.
It is high carrier mobility that makes graphene useful in such applications, and the results achieved by the Bosch-led team confirm this.
Comparing and contrasting materials, Roelver in his Graphene Week presentation showed that the worst case graphene scenarios roughly match a silicon reference.
In short, graphene provides for a high-performance magnetic sensor with low power and footprint requirements. In terms of hard numbers
the result shown by Roelver centred on a direct comparison between the sensitivity of a silicon-based Hall sensor with that of the Bosch-MPI graphene device.
whereas with the boron nitride and graphene device the figure is 7, 000. That is a two orders of magnitude improvement.
stressing that Bosch takes graphene very seriously indeed as a future commercial technology y
#First hospital light fixture to kill bacteria safely, continuously becomes commercially available in North america Indigo-Clean#is a light fixture manufactured through an exclusive licensing agreement with the University of Strathclyde in Glasgow, Scotland,
physicists have used graphene to build lightweight ultrasonic loudspeakers and microphones, enabling people to mimic bats
The diaphragms in the new devices are graphene sheets a mere one atom thick that have the right combination of stiffness,
Graphene consists of carbon atoms laid out in a hexagonal, chicken-wire arrangement, which creates a tough,
"There's a lot of talk about using graphene in electronics and small nanoscale devices, but they're all a ways away,
because we've worked out how to make the graphene and mount it, and it's easy to scale up."
"Arrayarraytwo years ago, Zhou built loudspeakers using a sheet of graphene for the diaphragm, and since then has been developing the electronic circuitry to build a microphone with a similar graphene diaphragm.
One big advantage of graphene is that the atom-thick sheet is so lightweight that it responds well to the different frequencies of an electronic pulse, unlike today's piezoelectric microphones and speakers.
This comes in handy when using ultrasonic transmitters and receivers to transmit large amounts of information through many different frequency channels simultaneously,
Graphene membranes are also more efficient, converting over 99 percent of the energy driving the device into sound,
"Graphene is a magical material; it hits all the sweet spots for a communications device, "he said.
The use of graphene allows the authors to obtain very flat frequency responses in a wide range of frequencies,
"Zettl noted that audiophiles would also appreciate the graphene loudspeakers and headphones, which have a flat response across the entire audible frequency range."
"A number of years ago, this device would have been darn near impossible to build because of the difficulty of making freestanding graphene sheets,
"But over the past decade the graphene community has come together to develop techniques to grow,
transport and mount graphene, so building a device like this is now very straightforward; the design is simple
termed phosphorene, in the same simple way as the Nobel-prize winning discovery of graphene. Unlike graphene, phosphorene is a semiconductor, like silicon,
which is the basis of current electronics technology.""Because phosphorene is so thin and light,
When the lubricant materials--graphene and diamond-like carbon (DLC)--slid against each other, the graphene began rolling up to form hollow cylindrical"scrolls"that helped to practically eliminate friction.
These so-called nanoscrolls represented a completely new mechanism for superlubricity a state in which friction essentially disappears."
The experimental setup consisted of small patches of graphene (a two-dimensional single-sheet form of pure carbon) sliding against a DLC-coated steel ball.
The graphene-DLC combination was registering a very low friction coefficient (a ratio that measures the force of friction between two surfaces),
This led to their discovery of the graphene nanoscrolls, which helped to fill in the blanks.
when the graphene patches were in an unscrolled state, "Deshmukh said. The computational scientists had an idea to overcome this issue.
The graphene patches spontaneously rolled around the nanodiamonds, which held the scrolls in place and resulted in sustained superlubricity.
The simulations showed that water suppresses the formation of scrolls by increasing the adhesion of graphene to the surface.
it would leave the graphene and nanodiamonds on one side of a moving part, and diamond-like carbon on the other side.
the graphene nanoscrolls could potentially work in humid environments as well.""Arraythe team's groundbreaking nanoscroll discovery would not have been possible without a supercomputer like Mira.
#Laser-induced graphene#super#for electronics Rice university scientists advanced their recent development of laser-induced graphene (LIG) by producing
The Rice lab of chemist James Tour discovered last year that firing a laser at an inexpensive polymer burned off other elements and left a film of porous graphene, the much-studied atom-thick
since their work to make vertically aligned supercapacitors with laser-induced graphene on both sides of a polymer sheet.
But the graphene retains its ability to move electrons quickly and gives it the quick charge
or graphenes could stabilize the polysulphides by physically trapping them. But in an unexpected twist, they discovered metal oxides could be the key.
and graduate students Connor Hart and Quan Pang also discovered that graphene oxide seems to work by a similar mechanism.
Looking at carbon-based graphene another atom-thick material with promise for chip development, researchers speculated that silicon atoms could be structured in a broadly similar way.
Akinwande, who also works on graphene transistors, sees value in silicene relationship to silicon, which chipmakers already know how to work with. part from introducing a new player in the playground of 2-D materials, silicene,
#Graphene displays clear prospects for flexible electronics Published in the scientific journal Nature Materials, University of Manchester and University of Sheffield researchers show that new 2d esigner materialscan be produced to create flexible, see-through and more efficient electronic devices.
The new research shows that graphene and related 2d materials could be utilised to create light emitting devices for the next-generation of mobile phones,
One-atom thick graphene was isolated first and explored in 2004 at The University of Manchester.
new possibilities for graphene based optoelectronics have now been realised. Freddie Withers, Royal Academy of Engineering Research Fellow at The University of Manchester, who led the production of the devices,
The new findings using a layer of one-atom-thick graphene deposited on top of a similar 2-D layer of a material called hexagonal boron nitride (hbn) are published in the journal Nano Letters.
The hybrid material blocks light when a particular voltage is applied to the graphene, while allowing a special kind of emission and propagation,
Light interaction with graphene produces particles called plasmons while light interacting with hbn produces phonons.
The properties of the graphene allow precise control over light, while hbn provides very strong confinement and guidance of the light.
says, his work represents significant progress on understanding tunable interactions of light in graphene-hbn.
The work is retty criticalfor providing the understanding needed to develop optoelectronic or photonic devices based on graphene and hbn,
#How to make continuous rolls of graphene Graphene is a material with a host of potential applications,
the need for a scalable and cost-effective method for continuous manufacturing of graphene films. That could finally change with a new process described in the journal Scientific Reports by researchers at MIT and the University of Michigan.
MIT mechanical engineering Associate professor A. John Hart, the paper senior author, says the new roll-to-roll manufacturing process described by his team addresses the fact that for many proposed applications of graphene
Making such quantities of graphene would represent a big leap from present approaches where researchers struggle to produce small quantities of graphene often pulling these sheets from a lump of graphite using adhesive tape,
or producing a film the size of a postage stamp using a laboratory furnace. But the new method promises to enable continuous production,
That could finally unleash applications for graphene, which has unique electronic and optical properties and is one of the strongest materials known.
and elsewhere to make graphene using a small vacuum chamber into which a vapor containing carbon reacts on a horizontal substrate,
where the graphene is formed on the ribbon. The chamber is heated to approximately 1, 000 degrees Celsius to perform the reaction.
high-quality single layer of graphene is created. When rolled 20 times faster, it still produces a coating,
but the graphene is of lower quality, with more defects. Some potential applications, such as filtration membranes
may require very high-quality graphene, but other applications, such as thin-film heaters may work well enough with lower-quality sheets,
So far, the new system produces graphene that is ot quite equal to the best that can be done by batch processing,
Further work on details such as pretreatment of the substrate to remove unwanted surface defects could lead to improvements in the quality of the resulting graphene sheets
such as between higher production rate and graphene quality. Then, he says, he next step is to understand how to push the limits,
Hart says that while this study focuses on graphene, the machine could be adapted to continuously manufacture other two-dimensional materials,
which his group is also studying. his is high-quality research that represents significant progress on the path to scalable production methods for large-area graphene,
It has the potential to lead to significantly lower production costs for graphene, if it can be scaled to larger copper-foil widths. d
#Breakthrough in graphene production could trigger revolution in artificial skin development A pioneering new technique to produce high-quality,
low cost graphene could pave the way for the development of the first truly flexible lectronic skin that could be used in robots.
Researchers from the University of Exeter have discovered an innovative new method to produce the wonder material Graphene significantly cheaper,
from Exeter Engineering department, believes the new discovery could pave the way for graphene-driven industrial revolutionto take place.
he vision for a raphene-driven industrial revolutionis motivating intensive research on the synthesis of high quality and low cost graphene.
Currently, industrial graphene is produced using a technique called Chemical Vapour Deposition (CVD. Although there have been significant advances in recent years in this technique,
which grows graphene in an industrial cold wall CVD system, a state-of-the-art piece of equipment recently developed by UK graphene company Moorfield.
This so-called nanocvd system is based on a concept already used for other manufacturing purposes in the semiconductor industry.
This shows to the semiconductor industry for the very first time a way to potentially mass produce graphene with present facilities rather than requiring them to build new manufacturing plants.
This new technique grows graphene 100 times faster than conventional methods reduces costs by 99
and look forward to seeing where it can take the graphene industry in the future. Professor Seigo Tarucha from the University of Tokyo, coordinator of the Global Center of Excellence for Physics at Tokyo university and director of the Quantum Functional System Research Group at Riken Center
he ability to manufacture high quality, large area graphene (at a low cost) is essential for advancing this exciting material from pure science and proof-of-concept into the realm of conventional and quantum electronic applications.
we are using Exeter CVD grown graphene instead of the exfoliated material in our graphene-based devices, whenever possible.
The research team used this new technique to create the first graphene-based transparent and flexible touch sensor.
and energy harvesting devices could be transformed by the unique properties of graphene. The extremely cost efficient procedure that we have developed for preparing graphene is of vital importance for the quick industrial exploitation of graphene.
At just one atom thick, graphene is the thinnest substance capable of conducting electricity. It is very flexible
and is one of the strongest known materials. The race has been on for scientists and engineers to adapt graphene for flexible electronics.
Professor Saverio Russo, co-author and also from the University of Exeter added: his breakthrough will nurture the birth of new generations of flexible electronics and offers exciting new opportunities for the realization of graphene-based disruptive technologies.
Source: University of Exete s
#Electrical engineers Break Power and Distance Barriers for Fiber optic communication Electrical engineers have broken key barriers that limit the distance information can travel in fiber optic cables
and detected using ferromagnetic metal contacts with a tunnel barrier consisting of single layer graphene between the metal and silicon NW.
The ferromagnetic metal/graphene tunnel barrier contacts used to inject and detect spin appear as blue,
The use of graphene as the tunnel barrier provides a low-resistance area product contact
and used a graphene tunnel barrier contact that produces excellent spin injection and also satisfies several key technical criteria:
Using intrinsic 2d layers such as graphene or hexagonal boron nitride as tunnel contacts on nanowires offers many advantages over conventional materials deposited by vapor deposition (such as Al2o3
The use of multilayer rather than single layer graphene in such structures may provide much higher values of the tunnel spin polarization because of band structure derived spin filtering effects predicted for selected ferromagnetic metal/multi
-layer graphene structures. This increase would further improve the performance of nanowire spintronic devices by providing higher signal to noise ratios
#Graphene flexes its electronic muscles Flexing graphene may be the most basic way to control its electrical properties, according to calculations by theoretical physicists at Rice university and in Russia.
and predictable in nanocones and should apply equally to other forms of graphene. The researchers discovered it may be possible to access
which the electronic properties of a sheet of graphene can be manipulated simply by twisting it a certain way.
The work will be of interest to those considering graphene elements in flexible touchscreens or memories that store bits by controlling electric dipole moments of carbon atoms
Perfect graphene an atom-thick sheet of carbon is a conductor, as its atomselectrical charges balance each other out across the plane.
But curvature in graphene compresses the electron clouds of the bonds on the concave side and stretches them on the convex side,
The researchers who published their results this month in the American Chemical Society Journal of Physical chemistry Letters discovered they could calculate the flexoelectric effect of graphene rolled into a cone of any size and length.
The researchers used density functional theory to compute dipole moments for individual atoms in a graphene lattice
and then figure out their cumulative effect They suggested their technique could be used to calculate the effect for graphene in other more complex shapes, like wrinkled sheets or distorted fullerenes,
several of which they also analyzed. hile the dipole moment is zero for flat graphene or cylindrical nanotubes,
Carbon nanotubes, seamless cylinders of graphene, do not display a total dipole moment, he said. While not zero, the vector-induced moments cancel each other out.
physicists have used graphene to build lightweight ultrasonic loudspeakers and microphones, enabling people to mimic bats
The diaphragms in the new devices are graphene sheets a mere one atom thick that have the right combination of stiffness
Graphene consists of carbon atoms laid out in a hexagonal, chicken-wire arrangement, which creates a tough,
or more years. here a lot of talk about using graphene in electronics and small nanoscale devices, but theye all a ways away, said Zettl,
because wee worked out how to make the graphene and mount it, and it easy to scale up. ettl,
UC Berkeley postdoctoral fellow Qin Zhou and colleagues describe their graphene microphone and ultrasonic radio in a paper appearing online this week in the Proceedings of the National Academy of Sciences.
Zhou built loudspeakers using a sheet of graphene for the diaphragm, and since then has been developing the electronic circuitry to build a microphone with a similar graphene diaphragm.
An atom-thick layer of carbon atoms, called graphene (black mesh), provides the vibrating diaphragm for both an ultrasonic microphone and loudspeaker.
Image credit: UC Berkeleyone big advantage of graphene is that the atom-thick sheet is so lightweight that it responds immediately to an electronic pulse, unlike today piezoelectric microphones and speakers.
This comes in handy when using ultrasonic transmitters and receivers to transmit large amounts of information through many different frequency channels simultaneously,
Graphene membranes are also more efficient converting over 99 percent of the energy driving the device into sound,
The use of graphene allows the authors to obtain very flat frequency responses in a wide range of frequencies,
and will permit a detailed study of the auditory pulses that are used by bats. ettl noted that audiophiles would also appreciate the graphene loudspeakers and headphones,
this device would have been darn near impossible to build because of the difficulty of making freestanding graphene sheets,
Zettl said. ut over the past decade the graphene community has come together to develop techniques to grow,
transport and mount graphene, so building a device like this is now very straightforward; the design is simple. ource:
#Graphene-Based Biosensor Could Detect Cancer within Minutes One of the main reasons why treating most cancers is such a difficult task is our inability to detect its presence before it becomes widespread.
The new, graphene-based immunosensor could soon lead to a quantum leap in cancer diagnosis. Image credit:
it took graphene to also make it sensitive to cancer. e showed experimentally that simply the addition of graphene led to a clear increase in the sensor signal, aid Dr. Georg Duesberg,
Consequently, materials scientists have been falling over themselves to discover the extraordinary properties of graphene, boron nitride, molybdenum disulphide, and so on.
The big advantage of black phosphorus over graphene is that it has a natural bandgap that physicists can exploit to make electronic devices
What more, black phosphorus is better at this even than graphene. Finally, they measured the current through the nanosheets
All this could mark an interesting step change in research associated with black phosphorus. Many people will have seen the excitement associated with the remarkable properties of graphene.
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