which can be applied as high performance electrodes for secondary batteries and fuel cells. Yung-Eun Sung is both a group leader at the Center for Nanoparticle Research at Institute for Basic Science*(IBS) and a professor at the Seoul National University.
lithium secondary batteries, sensors, and semiconductors
#A crystal wedding in the nanocosmos Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Vienna University of Technology and the Maria Curie-Sklodowska University Lublin have succeeded in embedding nearly perfect semiconductor crystals
into a silicon nanowire. With this new method of producing hybrid nanowires, very fast and multifunctional processing units can be accommodated on a single chip in the future.
Nano-optoelectronics are considered the cornerstone of future chip technology, but the research faces major challenges:
on the one hand, electronic components must be accommodated into smaller and smaller spaces. On the other hand, what are known as compound semiconductors are to be embedded into conventional materials.
In contrast to silicon, many of such semiconductors with extremely high electron mobility could improve performance of the most modern silicon-based CMOS technology.
Scientists from the HZDR, Vienna University of Technology and Maria Curie-Sklodowska University Lublin have now come a step closer to both these targets:
they integrated compound semiconductor crystals made of indium arsenide (Inas) into silicon nanowires, which are suited ideally for constructing increasingly compact chips.
This integration of crystals was the greatest obstacle for such"hetero-nanowires"until now: beyond the nanometer range, crystal lattice mismatch always led to numerous defects.
"while the implanted atoms form the indium arsenide crystals.""Dr. Wolfgang Skorupa, the head of the research group adds:"
"In the next step, the scientists want to implement different compound semiconductors into Silicon nanowires and also optimize the size and distribution of the crystals a
#Tiny laser sensor heightens bomb detection sensitivity New technology under development at the University of California,
UC Berkeley professor of mechanical engineering, has found a way to dramatically increase the sensitivity of a light-based plasmon sensor to detect incredibly minute concentrations of explosives.
They put the sensor to the test with various explosives 2 4-dinitrotoluene (DNT), ammonium nitrate and nitrobenzene and found that the device successfully detected the airborne chemicals at concentrations of 0. 67 parts per billion, 0. 4 parts per billion and 7. 2 parts
The researchers noted that this is much more sensitive than the published results to date for other optical sensors."
"Optical explosive sensors are very sensitive and compact, "said Zhang, who is also director of the Materials science Division at the Lawrence Berkeley National Laboratory and director of the National Science Foundation Nanoscale Science and Engineering Center at UC Berkeley."
"The ability to magnify such a small trace of an explosive to create a detectable signal is a major development in plasmon sensor technology,
"The new sensor could have many advantages over current bomb-screening methods.""Bomb-sniffing dogs are expensive to train
Our technology could lead to a bomb-detecting chip for a handheld device that can detect the tiny-trace vapor in the air of the explosive's small molecules."
"The sensor could also be developed into an alarm for unexploded land mines that are otherwise difficult to detect,
Unstable and hungry for electrons The nanoscale plasmon sensor used in the lab experiments is much smaller than other explosive detectors on the market.
It consists of a layer of cadmium sulfide, a semiconductor, laid on top of a sheet of silver with a layer of magnesium fluoride in the middle.
In designing the device the researchers took advantage of the chemical makeup of many explosives, particularly nitro-compounds such as DNT and its more well-known relative, TNT.
This quality increases the interaction of the molecules with natural surface defects on the semiconductor.
Potential use to sense hard-to-detect explosive"We think that higher electron deficiency of explosives leads to a stronger interaction with the semiconductor sensor"
Because of this, the researchers are hopeful that their plasmon laser sensor could detect pentaerythritol tetranitrate, or PETN, an explosive compound considered a favorite of terrorists.
Latest generation of plasmon sensors The sensor represents the latest milestone in surface plasmon sensor technology,
The ability to increase the sensitivity of optical sensors had traditionally been restricted by the diffraction limit,
The new device builds upon earlier work in plasmon lasers by Zhang's lab that compensated for this light leakage by using reflectors to bounce the surface plasmons back and forth inside the sensor similar to the way sound waves are reflected across the room
and using the optical gain from the semiconductor to amplify the light energy. Zhang said the amplified sensor creates a much stronger signal than the passive plasmon sensors currently available
which work by detecting shifts in the wavelength of light.""The difference in intensity is similar to going from a light bulb for a table lamp to a laser pointer,
Fortunately researchers have pinpointed now the breaking mechanism of several monolayer materials hundreds of times stronger than steel with exotic properties that could revolutionize everything from armor to electronics.
and whether they acted as metals semiconductors or insulators under strain. Toggling between or sustaining those conductive properties are particularly important for future applications in microelectronics.
Testing all the different atomic configurations for each material under strain boils down to a tremendous amount of computation Isaacs said.
#Nanophotonics experts create powerful molecular sensor Nanophotonics experts at Rice university have created a unique sensor that amplifies the optical signature of molecules by about 100 billion times.
Researchers at Rice's Laboratory for Nanophotonics (LANP) said the single-molecule sensor is about 10 times more powerful that previously reported devices."
"Ours and other research groups have been designing single-molecule sensors for several years, but this new approach offers advantages over any previously reported method,
"The ideal single-molecule sensor would be able to identify an unknown moleculeven a very small oneithout any prior information about that molecule's structure or composition.
"The optical sensor uses Raman spectroscopy, a technique pioneered in the 1930s that blossomed after the advent of lasers in the 1960s.
By using CARS in conjunction with a light amplifier made of four tiny gold nanodiscs,
Zhang said the quadrumer amplifiers are a key to SECARS, in part because they are created with standard e-beam lithographic techniques,
The manufacture of`super-black`carbon nanotube-based materials has required traditionally high temperatures preventing their direct application to sensitive electronics or materials with relatively low melting points.
which period Surrey Nanosystems successfully transferred its low-temperature manufacturing process from silicon to aluminum structures and pyroelectric sensors.
and long-term vibration and is suitable for coating internal components such as apertures baffles cold shields and Micro Electro Mechanical systems (MEMS)- type optical sensors.
and hence, optical properties of select antennas. Therefore, one can decide after fabrication, rather than before,
His research is centered on building better lithium ion batteries, primarily for personal electronics and electric vehicles. He is focused on the anode
but as electronics have become more powerful graphite's ability to be improved has been tapped virtually out.
Building smaller greener electronics In the drive to get small, Robert Wolkow and his lab at the University of Alberta are taking giant steps forward.
when using traditional transistor-based integrated circuits. That's why he and his research team are aiming to build entirely new technologies at the atomic scale."
"Our ultimate goal is to make ultra-low-power electronics because that's what is demanded most by the world right now,
"It could be as important as the transistor, "says Wolkow.""It lays the groundwork for a whole new basis of electronics,
and in particular, ultra-low-power electronics.""Wolkow and his team have built upon their earlier successes, modifying scanning tunnelling microscopes with their atom-wide microscope tip,
which emits ions instead of light at superior resolution. Like the needle of a record player, the microscopes can trace out the topography of silicon atoms, sensing surface features on the atomic scale.
"Much of their efforts initially will focus on creating hybrid technologiesdding atom-scale circuitry to conventional electronics such as GPS devices
#Designing ultra-sensitive biosensors for early personalised diagnostics A new type of high-sensitivity and low-cost sensors,
amplifying the light radiation in hot spots regions of the antenna, explains Pietro Giuseppe Gucciardi, a physicist at the Institute for Chemical-Physical Processes, affiliated with the Italian National Research Council CNR, in Messina,
She adds that these biosensors will need to be integrated with optical components, with electronics for reading out the measurements, software to process all data,
The team analyzed the solar cell activity of their nanohole interfaces by coating them with a semiconducting polymer and metal electrodes.
The newly developed material can be used as a substitute for graphene in solar cells and semiconductor chips.
and directly used the transparent electrodes for organic solar cells. The research outcome was introduced in Nanoscale a journal of Royal Society of Chemistry in the UK under the title of One-step Synthesis of Carbon Nanosheets Converted from a Polycylic Compound
and Their Direct Use as Transparent Electrodes of ITO-free Organic solar cells and was selected as a cover story in the January 21st edition in recognition for this innovative and superb research findings.
to close the gap between nanowires in an array to make them useful for high-performance electronics applications.
Nanowires are extremely fast, efficient semiconductors, but to be useful for electronics applications, they need to be packed together in dense arrays.
Researchers have struggled to find a way to put large numbers of nanowires together so that they are aligned in the same direction and only one layer thick."
because it allows sulfur to bind to the electrode in a finely divided manner, with relatively high loading.
And the rates of the key reactions at the sulfur electrode-electrolyte interface, which involve both electrons
In 2009, the International Technology Roadmap for Semiconductors (ITRS) selected carbon-based nanoelectronics to include carbon nanotubes
"the main hurdle (of carbon-based electronics) is our current inability to produce large amounts of identical nanostructureshere is no reliable way to directly produce a single CNT type such as will be needed in a large integrated system."
including flexible electronics such as antennas, chemical sensors and strain detectors.""It also would produce transparent electrodes for solar cells and organic light-emitting diodes,
Clem said. The method was inspired by industrial embossing processes in which a patterned mask is applied with high external pressure to create patterns in the substrate,
platinum and other metallic nanoparticles Clem said the researchers are now starting to work with semiconductors.
Importantly, they have applied the abiotic analogs to energy conversion systems. The confined water, that is water confined in micro-or mesopores,
and electric power storage improvement of battery capability and effort to develop new electrode materials have been demanded.
and easily-handled electrode material since its basic texture is composed of nanometric particles. The charge-discharge properties of simple L-BIOX/Li-metal cells were examined at current rates of 33. 3ma/g (0. 05c)
Notably the presence of minor components of Si and P in the original L-BIOX nanometric particles resulted in specific and well-defined electrode architecture.
Takada and colleagues proposed a unique approach to develop new electrode materials for Li-ion battery.
The findings have broad implications for the semiconductor industry and beyond. They show, for the first time, exactly how some memristors remember."
"The results could lead to a new approach to chip designne that involves using fine-tuned electrical signals to lay out integrated circuits after they're fabricated.
cheaper chips and computers inspired by biological brains in that they could perform many tasks at the same time.
which is used commonly in the semiconductor industry to help route electricity. They observed the metal atoms becoming charged ions, clustering with up to thousands of others into metal nanoparticles,
and forming a bridge between the electrodes at the opposite ends of the dielectric material. They demonstrated this process with several metals,
Graphene nanoribbons are good candidates for active materials in electronics being the channel of field-effect transistors coauthor Dr. Robert Vajtai at Rice university told Phys. org.
so it is a semiconductor. Explore further: Hybrid nanotube-graphene material promises to simplify manufacturing More information:
The researchers believe that the material lends itself to many kinds of highly sensitive sensors. The researchers made a thin film of graphene oxide by chemically exfoliating graphite into graphene flakes,
but is enhanced appreciably in ultrasmall semiconductor particles also called quantum dots as was demonstrated first by LANL researchers in 2004 (Schaller & Klimov Phys.
When it comes to electronics, silicon will now have to share the spotlight. In a paper recently published in Nature Communications,
energy-efficient hybrid circuit combining carbon nanotube thin film transistors with other thin film transistors. This hybrid could take the place of silicon as the traditional transistor material used in electronic chips,
since carbon nanotubes are more transparent, flexible, and can be processed at a lower cost. Electrical engineering professor Dr. Chongwu Zhou and USC Viterbi graduate students Haitian Chen
and Jialu Zhang developed this energy-efficient circuit by integrating carbon nanotube (CNT) thin film transistors (TFT) with thin film transistors comprised of indium, gallium and zinc oxide (IGZO)."
"Before then, we were working hard to try to turn carbon nanotubes into n-type transistors and then one day,
The inclusion of IGZO thin film transistors was necessary to provide power efficiency to increase battery life.
including Organic light Emitting Diodes (OLEDS), digital circuits, radio frequency identification (RFID) tags, sensors, wearable electronics, and flash memory devices.
stiff electrode objects are placed on several fixed locations on the patient's body. With this new hybridized circuit
however, electrodes could be placed all over the patient's body with just a single large but flexible object.
As a proof of concept, they achieved a scale ring oscillator consisting of over 1, 000 transistors.
Up to this point, all carbon nanotube-based transistors had a maximum number of 200 transistors.""We believe this is a technological breakthrough,
as digital circuits can be used in any electronics, "Chen said.""One day we'll be able to print these circuits as easily as newspapers."
#Charging portable electronics in 10 minutes Researchers at the University of California Riverside Bourns College of Engineering have developed a three-dimensional silicon-decorated cone-shaped carbon nanotube cluster architecture for lithium ion battery anodes that could enable charging of portable
electronics in 10 minutes instead of hours. Lithium ion batteries are the rechargeable battery of choice for portable electronic devices and electric vehicles.
But they present problems. Batteries in electric vehicles are responsible for a significant portion of the vehicle mass.
And the size of batteries in portable electronics limits the trend of downsizing. Silicon is a type of anode material that is receiving a lot of attention
which facilitates charge and thermal transfer in the electrode system. Two the cone-shaped architecture offers small interpenetrating channels for faster electrolyte access into the electrode
which may enhance the rate performance. Explore further: Silly Putty material inspires better batterie e
#Technology using microwave heating may impact electronics manufacture Engineers at Oregon State university have shown successfully that a continuous flow reactor can produce high-quality nanoparticles by using microwave-assisted heating essentially the same forces
Improved LED lighting is one possibility, as well as better TVS with more accurate colors. Wider use of solid state lighting might cut power use for lighting by nearly 50 percent nationally.
Cell phones and other portable electronic devices could use less power and last longer on a charge.
This new form of solid stable light-sensitive nanoparticles called colloidal quantum dots could lead to cheaper and more flexible solar cells as well as better gas sensors infrared lasers infrared light emitting diodes and more.
Collecting sunlight using these tiny colloidal quantum dots depends on two types of semiconductors: n-type which are rich in electrons;
-and p-type layers simultaneously not only boosts the efficiency of light absorption it opens up a world of new optoelectronic devices that capitalize on the best properties of both light and electricity.
For the average person this means more sophisticated weather satellites remote controllers satellite communication or pollution detectors.
#Shatterproof screens that save smartphones University of Akron polymer scientists have developed a transparent electrode that could change the face of smartphones, literally,
In a recently published scientific paper, researchers demonstrated how a transparent layer of electrodes on a polymer surface could be extraordinarily tough and flexible,
Due to its flexibility, the transparent electrode can be fabricated in economical, mass-quantity rolls.""We expect this film to emerge on the market as a true ITO competitor,
The team's findings are published in the American Chemical Society's journal ACS Nano in the article titled"A Tough and High-performance Transparent Electrode from a Scalable and Transfer-Free Method
New nanotech may provide power storage in electric cables clothes Imagine being able to carry all the juice you needed to power your MP3 PLAYER, smartphone and electric car in the fabric of your jacket?
and development of electrical vehicles, space-launch vehicles and portable electronic devices. By being able to store
It is possible to further miniaturize the electronic devices or the space that has been used previously for batteries could be used for other purposes.
which created an electrode. Two electrodes are needed for the powerful energy storage. So they had to figure out a way to create a second electrode.
They did it-this by adding a very thin plastic sheet around the whiskers and wrapping it around using a metal sheath (the second electrode) after generating nanowhiskers on it (the second electrode and outer covering).
The layers were glued then together with a special gel. Because of the insulationthe nanowhisker layer is insulating,
the inner copper wire retains its ability to channel electricity, the layers around the wire independently store powerful energy.
In other words, Thomas and his team created a supercapacitor on the outside of the copper wire. Supercapcitors store powerful energy,
#Nanotechnology takes on diabetes A sensor which can be used to screen for diabetes in resource-poor settings has been developed by researchers
A low-cost, reusable sensor which uses nanotechnology to screen for and monitor diabetes and other conditions, has been developed by an interdisciplinary team of researchers from the University of Cambridge, for use both in clinics and home settings.
The sensors use nanotechnology to monitor levels of glucose, lactate and fructose in individuals with diabetes or urinary tract infections
Earlier this year, clinical trials of the sensors were carried out at Addenbrooke's Hospital to monitor glucose levels in 33 diabetic patients.
The sensors developed by the Cambridge team are made using laser light, which organises metal nanoparticles into alternating layers in thin gel films to produce the sensors in a matter of seconds.
When glucose, lactate or fructose concentrations are high in a sample, the sensor changes colour.
The exact concentration can be determined by visually comparing the colour to a reference chart, or the image can be processed automatically by a smartphone application.
the sensors showed improved performance over commercial glucose test strips read by an automated reader,
Additionally, the sensors can be produced at a fraction of the cost of commercially-available test strips.
A single sensor would cost 20 pence to produce, and can be reused up to 400 times,
The use of lasers means that the sensors can be manufactured easily at scale.""These sensors can be used to screen for diabetes in resource-poor countries,
where disposable test strips and other equipment are simply not affordable, "said Ali Yetisen, a Phd candidate in the Department of Chemical engineering & Biotechnology,
"The value of these reusable sensors will be realised when they are mass produced and adopted as a diagnostic tool for routine diabetes screening,
#New method stabilizes common semiconductors for solar fuels generation Researchers around the world are trying to develop solar-driven generators that can split water yielding hydrogen gas that could be used as clean fuel.
Semiconductors like silicon and gallium arsenide are excellent light absorberss is clear from their widespread use in solar panels.
Now Caltech researchers at the Joint Center for Artificial Photosynthesis (JCAP) have devised a method for protecting these common semiconductors from corrosion even as the materials continue to absorb light efficiently.
and now these technologically important semiconductors are back on the table. The research led by Shu Hu a postdoctoral scholar in chemistry at Caltech appears in the May 30 issue of the journal Science.
and numerous techniques for coating the common light-absorbing semiconductors. The problem has been that if the protective layer is too thin the aqueous solution penetrates through
and corrodes the semiconductor. If on the other hand the layer is too thick it prevents corrosion but also blocks the semiconductor from absorbing light and keeps electrons from passing through to reach the catalyst that drives the reaction.
At Caltech the researchers used a process called atomic layer deposition to form a layer of titanium dioxide (Tio2) material found in white paint and many toothpastes and sunscreensn single crystals of silicon gallium arsenide
or gallium phosphide. The key was used that they a form of Tio2 known as leaky Tio2ecause it leaks electricity.
First made in the 1990s as a material that might be useful for building computer chips leaky oxides were rejected as undesirable because of their charge-leaking behavior.
what was needed for this solar fuel generator application Deposited as a film ranging in thickness between 4 and 143 nanometers the Tio2 remained optically transparent on the semiconductor crystalsllowing them to absorb lightnd protected them from corrosion
if applied using an inexpensive less-controlled application technique such as painting or spraying the Tio2 onto a semiconductor.
Also thus far the Caltech team has tested only the coated semiconductors for a few hundred hours of continuous illumination.
Chuang adds Every part of the cell except the electrodes for now can be deposited at room temperature in air out of solution.
#Flexible transparent thin film transistors raise hopes for flexible screens (Phys. org) he electronics world has been dreaming for half a century of the day you can roll a TV up in a tube.
Last year, Samsung even unveiled a smartphone with a curved screenut it was solid, not flexible;
see-through 2-D thin film transistors. These transistors are just 10 atomic layers thickhat's about how much your fingernails grow per second.
Transistors are the basis of nearly all electronics. Their two settingsn or offictate the 1s and 0s of computer binary language.
Thin film transistors are a particular subset of these that are used typically in screens and displays.
Virtually all flat-screen TVS and smartphones are made up of thin film transistors today; they form the basis of both LEDS and LCDS (liquid crystal displays."
"This could make a transparent, nearly invisible screen,"said Andreas Roelofs, a coauthor on the paper and interim director of Argonne's Center for Nanoscale Materials."
"Imagine a normal window that doubles as a screen whenever you turn it on, for example."
"To measure how good a transistor is, you measure its on-off ratioow completely can it turn off the current?
In most thin film transistors, the material starts to crack, which, as you might imagine,
"The transistors also maintained performance over a wide range of temperatures (from-320°F to 250°F), a useful property in electronics,
To build the transistors, the team started with a trick that earned its original University of Manchester inventors the Nobel prize:
and hole conduction necessary for making transistors with logic gates and other p-n junction devices,"said Argonne scientist and coauthor Anirudha Sumant.
Then they used chemical deposition to grow sheets of other materials on top to build the transistor layer by layer.
#Atomic force microscope systems take a tip from nanowires (Phys. org) In response to requests from the semiconductor industry a team of PML researchers has demonstrated that atomic force microscope (AFM) probe
tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon
or platinum tips in measurements of critical importance to microchip fabrication nanobiotechnology and other endeavors.
In addition the scientists have invented a means of simultaneously using the nanowire tips as LEDS to illuminate a tiny sample region with optical radiation
and Synthesis of 3d Nanostructures in the Quantum Electronics and Photonics Division is that if you deform them even a little bit
and optoelectronic devices Bertness says. At present only a few Gan probes can be made at once but the team is at work on developing ideas for producing them in wafer-scale quantities.
so that it functions as an LED. Optical radiation can serve to excite the sample in a different way from the microwave signal
and nanometer scale is crucial from semiconductor electronics to biochemistry and medicine. Explore further: High-resolution microscopy technique resolves individual carbon nanotubes under ambient condition c
According to Koskinen the observation advances research in nanoelectronics and optoelectronics because it markedly simplifies the interpretation and understanding of the electronic and optical properties of layered materials.
New structural'supercaps'take a lickin'keep on workin'Imagine a future in which our electrical gadgets are limited no longer by plugs and external power sources.
The new device that Pint and Westover has developed is a supercapacitor that stores electricity by assembling electrically charged ions on the surface of a porous material,
supercaps can charge and discharge in minutes, instead of hours, and operate for millions of cycles, instead of thousands of cycles like batteries.
In a paper appearing online May 19 in the journal Nano Letters, Pint and Westover report that their new structural supercapacitor operates flawlessly in storing
"In an unpackaged, structurally integrated state our supercapacitor can store more energy and operate at higher voltages than a packaged, off-the-shelf commercial supercapacitor, even under intense dynamic and static forces,
"Pint said. One area where supercapacitors lag behind batteries is in electrical energy storage capability: Supercaps must be larger and heavier to store the same amount of energy as lithium-ion batteries.
However, the difference is not as important when considering multifunctional energy storage systems.""Battery performance metrics change when you're putting energy storage into heavy materials that are needed already for structural integrity,
"said Pint.""Supercapacitors store ten times less energy than current lithium-ion batteries, but they can last a thousand times longer.
That means they are suited better for structural applications. It doesn't make sense to develop materials to build a home, car chassis,
"Westover's wafers consist of electrodes made from silicon that have been treated chemically so they have nanoscale pores on their inner surfaces
Sandwiched between the two electrodes is a polymer film that acts as a reservoir of charged ions, similar to the role of electrolyte paste in a battery.
When the electrodes are pressed together, the polymer oozes into the tiny pores in much the same way that melted cheese soaks into the nooks and crannies of artisan bread in a Panini.
"The biggest problem with designing load-bearing supercaps is preventing them from delaminating, "said Westover.""Combining nanoporous material with the polymer electrolyte bonds the layers together tighter than superglue."
"The use of silicon in structural supercapacitors is suited best for consumer electronics and solar cells, but Pint and Westover are confident that the rules that govern the load-bearing character of their design will carry over to other materials, such as carbon nanotubes and lightweight porous metals like aluminum.
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