#New material allows for ultra-thin solar cells Extremely thin, semitransparent, flexible solar cells could soon become reality.
At the Vienna University of Technology, Thomas Mueller, Marco Furchi and Andreas Pospischil have managed to create a semiconductor structure consisting of two ultra-thin layers,
which appears to be suited excellently for photovoltaic energy conversion Several months ago, the team had produced already an ultra-thin layer of the photoactive crystal tungsten diselenide.
creating a designer-material that may be used in future low-cost solar cells. With this advance the researchers hope to establish a new kind of solar cell technology.
Ultra-thin materials, which consist only of one or a few atomic layers are currently a hot topic in materials science today.
"We had already been able to show that tungsten diselenide can be used to turn light into electric energy
But a solar cell made only of tungsten diselenide would require countless tiny metal electrodes tightly spaced only a few micrometers apart.
The heterostructure can now be used to build large-area solar cells. When light shines on a photoactive material single electrons are removed from their original position.
if the energies of the electrons in both layers are tuned exactly the right way. In the experiment, this can be done using electrostatic fields.
Florian Libisch and Professor Joachim Burgdörfer (TU Vienna) provided computer simulations to calculate how the energy of the electrons changes in both materials
and which voltage leads to an optimum yield of electrical power.""One of the greatest challenges was to stack the two materials,
the solar cell will not work.""Eventually, this feat was accomplished by heating both layers in vacuum and stacking it in ambient atmosphere.
and converted into electric energy. The material could be used for glass fronts, letting most of the light in,
but still creating electricity. As it only consists of a few atomic layers, it is extremely light weight (300 square meters weigh only one gram),
but increase the electrical power o
#Surprise discovery could see graphene used to improve health (Phys. org) chance discovery about the'wonder material'graphene already exciting scientists because of its potential uses in electronics,
energy storage and energy generation takes it a step closer to being used in medicine and human health.
Strategic Energy resources Ltd and an expert in polarized light imaging, Dr. Rudolf Oldenbourg from the Marine Biological Laboratory, USA,
CEO of Strategic Energy resources Ltd said the collaboration with Monash was progressing well.""We are pleased so to be associated with Dr Majumder's team at Monash University.
The research was made possible by an ARC Linkage grant awarded to Strategic Energy resources Ltd and Monash University and was the first linkage grant for graphene research in Australia s
#Nanoscale details of electrochemical reactions in electric vehicle battery materials Using a new method to track the electrochemical reactions in a common electric vehicle battery material under operating conditions,
The results, published August 4, 2014, in Nature Communications, could provide guidance to inform battery makers'efforts to optimize materials for faster-charging batteries with higher capacity."
"Our work was focused on developing a method to track structural and electrochemical changes at the nanoscale as the battery material was charging,
or positive electrode, of electrical vehicle batteries-as the battery charged.""We wanted to catch
known as delithiation, is the key to recharging the battery to its fullest capacity so it will be able to provide power for the longest possible period of time.
Understanding the subtle details of why that doesn't always happen could ultimately lead to ways to improve battery performance,
Many previous methods used to analyze such battery materials have produced data that average out effects over the entire electrode.
The scientists used these methods to analyze samples made up of multiple nanoscale particles in a real battery electrode under operating conditions (in operando.
they also conducted the same in operando study using smaller amounts of electrode material than would be found in a typical battery.
The detailed images and spectroscopic information reveal unprecedented insight into why fast charging reduces battery capacity.
and could give industry guidance to help them develop a future fast-charge/high-capacity battery,
"So rather than focusing only on the battery materials'individual features, manufacturers might want to look at ways to prepare the electrode
"These discoveries provide the fundamental basis for the development of improved battery materials, "said Jun Wang."
"In addition, this work demonstrates the unique capability of applying nanoscale imaging and spectroscopic techniques in understanding battery materials with a complex mechanism in real battery operational conditions."
"The paper notes that this in operando approach could be applied in other fields, such as studies of fuel cells and catalysts,
which conducts electricity and can be printed by a standard inkjet printer. The graphene-based ink enables cost-effective printed electronics on plastic.
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.
these materials enhance the performance of secondary batteries and drive down the cost of producing fuel cells.
This process using common laboratory reagent, sodium hydroxide (Naoh) and heteroatom-containing organic solvents as precursors.
In addition, the lithium-ion batteries that had applied modified graphenes to it, exhibited a higher capacity than the theoretical capacity of graphite
which was used previously in lithium-ion batteries. It presented high chemical stability which resulted in no capacity degradation in charge and discharge experiments.
alternative chemical material by demonstrating performance comparable to that of the expensive platinum catalyst used for the cathode of fuel cell batteries.
, florine, boron, phosphorus) which can then increase the method's potential applications in fuel cells 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
but sustaining the confined energy was challenging because light tends to dissipate at a metal's surface.
"The difference in intensity is similar to going from a light bulb for a table lamp to a laser pointer,
and re-emitted into another energy level that differs from their initial level. By measuring and analyzing these re-emitted photons through Raman spectroscopy,
using a simple SEM operating at only a fraction of the electron energies of previous work,
#Sand-based lithium ion batteries that outperform standard by three times (Phys. org) esearchers at the University of California, Riverside's Bourns College of Engineering have created a lithium ion battery that outperforms the current industry standard by three times.
environmentally friendly way to produce high performance lithium ion battery anodes,"said Zachary Favors, a graduate student working with Cengiz and Mihri Ozkan, both engineering professors at UC Riverside.
His research is centered on building better lithium ion batteries, primarily for personal electronics and electric vehicles. He is focused on the anode
or negative side of the battery. Graphite is the current standard material for the anode,
That porosity has proved to be the key to improving the performance of the batteries built with the nano-silicon l
QSI plans to demonstrate the potential of these"extremely green"circuits that can make use of smaller, longer-lasting batteries.
One possibility is to use hybrid solar cells that combine silicon nanowires with low-cost, photoresponsive polymers. The high surface area and confined nature of nanowires allows them to trap significant amounts of light for solar cell operations.
Unfortunately, these thin, needle-like structures are very fragile and tend to stick together when the wires become too long.
One significant problem, notes Wang, is control of the initial stages of nanohole formation crucial period that can often induce defects into the solar cell.
The team analyzed the solar cell activity of their nanohole interfaces by coating them with a semiconducting polymer and metal electrodes.
which impede the solar cell industry, "says Wang.""In addition, this approach can be transferred easily to silicon thin films to develop thin-film siliconolymer hybrid solar cells with even higher efficiency. e
#Making dreams come true: Making graphene from plastic? Graphene is gaining heated attention dubbed a wonder material with great conductivity flexibility and durability.
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.
and move the manufactured graphene to another board such as a solar cell substrate. In this process the quality quickly degrades as it is prone to wrinkles or cracks.
In addition the new method can be used directly as solar cell without any additional process. The research team synthesized a polymer with a rigid ladder structure namely PIM-1 (Polymer of intrinsic microporosity-1) to form the#through the simpole process
"One application the group is now exploring is a thin film solar cell, made of densely packed nanowires,
that could harvest energy from light much more efficiently than traditional thin-film solar cells s
#Chemists seek state-of-the-art lithium-sulfur batteries When can we expect to drive the length of Germany in an electric car without having to top up the battery?
Chemists at the NIM Cluster at LMU and at the University of Waterloo in Ontario, Canada, have synthesized now a new material that could show the way forward to state-of-the-art lithium-sulfur batteries.
Whether or not the future of automotive traffic belongs to the softly purring electric car depends largely on the development of its batteries.
The industry is currently placing most of its hopes in lithium-sulfur batteries, which have a very high storage capacity.
the lithium-sulfur battery still presents several major challenges that need to be resolved until it can be integrated into cars.
For example, both the rate and the number of possible charge-discharge cycles need to be increased before the lithium-sulfur battery can become a realistic alternative to lithium-ion batteries.
Lots of pores for sulfur The chemists Professor Thomas Bein (LMU), Coordinator of the Energy conversion Division of the Nanosystems Initiative Munich, Professor Linda Nazar (University of Waterloo, Waterloo Institute
And the rates of the key reactions at the sulfur electrode-electrolyte interface, which involve both electrons
and storage of electrical energy,"says Thomas Bein.""We in the NIM Cluster will continue to collaborate closely with our colleagues in the Bavarian Soltech Network
"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
able to transmit light and electricity with specific characteristics. This pressure-regulated fine-tuning of particle separation enables controlled investigation of distance-dependent optical and electrical phenomena.
This interaction enables the energy transfer between the internalized molecules says Raymo director of the UM laboratory for molecular photonics.
If the complementary energy donors and acceptors are loaded separately and sequentially the transfer of energy between them occurs exclusively within the intracellular space he says.
As the energy transfer takes place the acceptors emit a fluorescent signal that can be observed with a microscope.
Essential to this mechanism are the noncovalent bonds that loosely hold the supramolecular constructs together.
The next phase of this investigation involves demonstrating that this method can be used to do chemical reactions inside cells instead of energy transfers.
and construction of smart nanochannels and applied the nanochannels in energy conversion systems. The author thought the inner surface property was the base for confined transportation.
such as cellular signal transfer, energy conversion, potential adjusting, matter exchange and systemic function adjusting. One remarkable example is the electric eel,
Importantly, they have applied the abiotic analogs to energy conversion systems. The confined water, that is water confined in micro-or mesopores,
biological ion channels played key roles for high efficient energy conversion in organisms due to its nanoscale effect and ion selectivity.
which ensures its energy conversion efficiency far beyond the traditional manual energy device. Therefore, inspired by living systems,
which can greatly enhance the conversion efficiency helping us to solve the global energy shortage e
#Bacterial nanometric amorphous Fe-based oxide as lithium-ion battery anode material Leptothrix ochracea is a species of iron-oxidizing bacteria that exists in natural hydrospheres where groundwater outwells worldwide.
but Jun Takada and colleagues at Okayama University discovered unexpected industrial functions of L-BIOX such as a great potential as an anode material in lithium-ion battery.
Since use of the battery that is a powerful electric source for portable electric devices has expanded to a variety of new areas such as transportation
and electric power storage improvement of battery capability and effort to develop new electrode materials have been demanded.
The general processes of nanosizing and appropriate surface modification which are required for tuning the battery property are complicated
Takada and colleagues proposed a unique approach to develop new electrode materials for Li-ion battery.
A Potential Lithium-Ion Battery Anode Material. Hideki Hashimoto Genki Kobayashi Ryo Sakuma Tatsuo Fujii Naoaki Hayashi Tomoko Suzuki Ryoji Kanno Mikio Takano and Jun Takada.
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,
stays put after the electrical power is turned off in the device. So when researchers turn the power back on
which could make it a much lighter weight replacement for copper transmission lines. The researchers believe that the material lends itself to many kinds of highly sensitive sensors.
such as in batteries for portable devices, where reduced weight is also highly desirable. Another property of these materials is that they conduct sound and elastic waves very uniformly,
#New approach may be key to quantum dot solar cells with real gains in efficiency (Phys. org) Los alamos researchers have demonstrated an almost fourfold boost of the carrier multiplication yield with nanoengineered quantum dots.
Quantum dots are novel nanostructures that can become the basis of the next generation of solar cells capable of squeezing additional electricity out of the extra energy of blue and ultraviolet photons.
Typical solar cells absorb a wide portion of the solar spectrum but because of the rapid cooling of energetic (or'hot')charge carriers the extra energy of blue and ultraviolet solar photons is wasted in producing heat said Victor Klimov director of the Center for Advanced Solar Photophysics
(CASP) at Los alamos National Laboratory. In principle this lost energy can be recovered by converting it into additional photocurrent via carrier multiplication.
In that case collision of a hot carrier with a valence-band electron excites it across the energy gap Klimov said.
In this way absorption of a single photon from the high-energy end of the solar spectrum produces not just one
Carrier multiplication is inefficient in the bulk solids used in ordinary solar cells but is enhanced appreciably in ultrasmall semiconductor particles also called quantum dots as was demonstrated first by LANL researchers in 2004 (Schaller & Klimov Phys.
Klimov explained This strong enhancement is derived primarily from the unusually slow phonon relaxation of hot holes that become trapped in high-energy states within the thick Cdse shell.
Applied together these strategies might provide a practical route to nanostructures exhibiting carrier multiplication performance approaching the limits imposed by energy conservation n
The inclusion of IGZO thin film transistors was necessary to provide power efficiency to increase battery life.
such as the fine structures of cell components or modern catalysts and batteries. Until now, such fine details could only be rendered visible with the aid of electron microscopes
Thus far, for instance, materials such as chalk, cement, solar cells and fossils have been studied in collaboration with various research institutions n
#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
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 because its total charge capacity is 10 times higher than commercial graphite based lithium ion battery anodes.
Consider a packaged battery full-cell. Replacing the commonly used graphite anode with silicon anodes will potentially result in a 63 percent increase of total cell capacity and a battery that is 40 percent lighter and smaller.
In a paper Silicon Decorated Cone Shaped Carbon nanotube Clusters for Lithium ion battery Anode recently published in the journal Small UC Riverside researchers developed a novel structure of three-dimensional silicon decorated cone-shaped
carbon nanotube clusters architecture via chemical vapor deposition and inductively coupled plasma treatment. Lithium ion batteries based on this novel architecture demonstrate a high reversible capacity and excellent cycling stability.
The architecture demonstrates excellent electrochemical stability and irreversibility even at high charge and discharge rates nearly 16 times faster than conventionally used graphite based anodes.
The researchers believe the ultrafast rate of charge and discharge can be attributed to two reasons said Wei Wang lead author of the paper.
Two the cone-shaped architecture offers small interpenetrating channels for faster electrolyte access into the electrode
#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
It could change everything from the production of cell phones and televisions to counterfeit-proof money, improved solar energy systems or quick identification of troops in combat.
"This might be the big step that takes continuous flow reactors to large-scale manufacturing, "said Greg Herman, an associate professor and chemical engineer in the OSU College of Engineering."
and in the past that was done best only in small reactors. The new research has proven that microwave heating can be done in larger systems at high speeds.
"Combining continuous flow with microwave heating could give us the best of both worlds large, fast reactors with perfectly controlled particle size."
Other materials can be synthesized using this reactor for different applications, including copper zinc tin sulfide and copper indium diselenide for solar cells.
New Oregon jobs and businesses are already evolving from this work. OSU researchers have applied for a patent on aspects of this technology,
#New class of nanoparticle brings cheaper lighter solar cells outdoors Think those flat glassy solar panels on your neighbour's roof are the pinnacle of solar technology?
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.
-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.
Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stabilityo one has shown that before.
But improved performance is just a start for this new quantum dot-based solar cell architecture. The powerful little dots could be mixed into inks
The field of colloidal quantum dot photovoltaics requires continued improvement in absolute performance or power conversion efficiency said Sargent.
New breed of solar cells: Quantum dot photovoltaics set new record for efficiency in such devices More information:
Air-stable n-type colloidal quantum dot solids DOI: 10.1038/nmat400 a
#Shatterproof screens that save smartphones University of Akron polymer scientists have developed a transparent electrode that could change the face of smartphones, literally,
Taox-capped Pt nanoparticles as efficient catalysts for polymer electrolyte fuel cells More information: Covert thermal barcodes based on phase change nanoparticles Scientific Reports 4 Article number:
#Electrical cables that store energy? 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?
but it may become a reality thanks to breakthrough technology developed at a University of Central Florida research lab. So far electrical cables are used only to transmit electricity.
However, nanotechnology scientist and professor Jayan Thomas and his Ph d. student Zenan Yu have developed a way to both transmit and store electricity in a single lightweight copper wire.
special fibers could also be developed with nanostructures to conduct and store energy. More immediate applications could be seen in the design
and conduct energy on the same wire, heavy, space-consuming batteries could become a thing of the past.
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.
In the case of launch vehicles that could potentially lighten the load, making launches less costly,
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,
like that needed to start a vehicle or heavy-construction equipment. Although more work needs to be done,
if flexible solar cells and these fibers were used in tandem to make a jacket, it could be used independently to power electronic gadgets and other devices."
Semiconductors like silicon and gallium arsenide are excellent light absorberss is clear from their widespread use in solar panels.
The key was used that they a form of Tio2 known as leaky Tio2ecause it leaks electricity.
#New breed of solar cells: Quantum dot photovoltaics set new record for efficiency in such devices Solar-cell technology has advanced rapidly as hundreds of groups around the world pursue more than two dozen approaches using different materials technologies
and approaches to improve efficiency and reduce costs. Now a team at MIT has set a new record for the most efficient quantum dot cells a type of solar cell that is seen as especially promising because of its inherently low cost versatility and light weight.
While the overall efficiency of this cell is still low compared to other types about 9 percent of the energy of sunlight is converted to electricity the rate of improvement of this technology is one of the most rapid seen for a solar technology.
The development is described in a paper published in the journal Nature Materials by MIT professors Moungi Bawendi and Vladimir Buloviä#and graduate students Chia-Hao Chuang and Patrick Brown.
These minuscule particles are very effective at turning light into electricity and vice versa. Since the first progress toward the use of quantum dots to make solar cells Bawendi says The community in the last few years has started to understand better how these cells operate and
what the limitations are. The new work represents a significant leap in overcoming those limitations increasing the current flow in the cells
and thus boosting their overall efficiency in converting sunlight into electricity. Many approaches to creating low-cost large-area flexible and lightweight solar cells suffer from serious limitations such as short operating lifetimes
when exposed to air or the need for high temperatures and vacuum chambers during production. By contrast the new process does not require an inert atmosphere
The solar cell produced by the team has now been added to the National Renewable energy Laboratories'listing of record-high efficiencies for each kind of solar-cell technology.
The overall efficiency of the cell is still lower than for most other types of solar cells.
And the new technology has important advantages notably a manufacturing process that is far less energy-intensive than other types.
But his team's research since then has demonstrated clearly quantum dots'potential in solar cells he adds.
Arthur Nozik a research professor in chemistry at the University of Colorado who was involved not in this research says This result represents a significant advance for the applications of quantum dot films and the technology of low-temperature solution-processed quantum dot photovoltaic cells.#
#There is still a long way to go before quantum dot solar cells are commercially viable but this latest development is a nice step toward this ultimate goal.
Improved performance and stability in quantumâ dot solar cells through band alignmentâ engineering. Chia-Hao M. Chuang et al.
in collaboration with colleagues at the University of Michigan, have developed a 3-D artificial enzyme cascade that mimics an important biochemical pathway that could prove important for future biomedical and energy applications.
taking advantage of the binding properties of the chemical building blocks of DNA, twist and self-assemble DNA into evermore imaginative 2-and 3-dimensional structures for medical, electronic and energy applications.
used in our bodies for the digestion of food into sugars and energy during human metabolism, for example."
since they supply most of the energy of a cell, "said Walter."Work with these enzymes could lead to future applications in green energy production such as fuel cells using biomaterials for fuel."
"In the pathway, G6pdh uses the glucose sugar substrate and a cofactor called NAD to strip hydrogen atoms from glucose and transfer to the next enzyme, MDH,
This intriguing prospect is one of the reasons for the current interest in building the capacity to store electrical energy directly into a wide range of products,
such as a laptop whose casing serves as its battery, or an electric car powered by energy stored in its chassis,
or a home where the dry wall and siding store the electricity that runs the lights and appliances.
It also makes the small dull grey wafers that graduate student Andrew Westover and Assistant professor of Mechanical engineering Cary Pint have made in Vanderbilt's Nanomaterials
and Energy Devices Laboratory far more important than their nondescript appearance suggests.""These devices demonstrate for the first time as far as we can tell that it is possible to create materials that can store
and discharge significant amounts of electricity while they are subject to realistic static loads and dynamic forces,
"When you can integrate energy into the components used to build systems, it opens the door to a whole new world of technological possibilities.
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,
instead of storing it in chemical reactions the way batteries do. As a result supercaps can charge
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,
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,
or aerospace vehicle if you have to replace them every few years because they go dead."
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.
"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.
The intensity of interest in"multifunctional"devices of this sort is reflected by the fact that the U s. Department of energy's Advanced Research Project Agency for Energy is investing $8. 7 million in research projects that focus specifically on incorporating energy storage into structural materials.
There have also been recent press reports of several major efforts to develop multifunctional materials or structural batteries for use in electric vehicles and for military applications.
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