but not much of the rest of the spectrum since that would increase the energy that is reradiated by the material
The material works as part of a solar-thermophotovoltaic (STPV) device: The sunlight's energy is converted first to heat
which then causes the material to glow emitting light that can in turn be converted to an electric current.
In this paper the authors demonstrated in a system designed to withstand high temperatures the engineering of the optical properties of a potential solar thermophotovoltaic absorber to match the sun's spectrum.
Of course much work remains to realize a practical solar cell however the work here is one of the most important steps in that process.
We achieved this using graphene a material that can conduct electricity and interpret touch commands
which can consume a great deal of energy particularly in computing applications. Researchers are therefore searching for ways to harness other properties of electrons such as the'spin'of an electron as data carriers in the hope that this will lead to devices that consume less power.
#Solar cell compound probed under pressure Gallium arsenide Gaas a semiconductor composed of gallium and arsenic is well known to have physical properties that promise practical applications.
In the form of nanowires and nanoparticles it has particular potential for use in the manufacture of solar cells
When semiconducting materials are subjected to an input of a specific energy bound electrons can be moved to higher energy conducting states.
The specific energy required to make this jump to the conducting state is defined as the band gap.
#Controlling photoluminescence with silicon nanophotonics for better devices Silicon nanowires have a great deal of potential in future high-performance electronic sensing and energy devices.
Silicon nanoparticles such as those in RM 8027 are being studied as alternative semiconductor materials for next-generation photovoltaic solar cells and solid-state lighting,
and as a replacement for carbon in the cathodes of lithium batteries. Another potential application comes from the fact that silicon crystals at dimensions of 5 nanometers
#Self-organized indium arsenide quantum dots for solar cells Kouichi Yamaguchi is recognized internationally for his pioneering research on the fabrication and applications of'semiconducting quantum dots'(QDS.
when irradiated with light or under external electromagnetic fields. Our main interest in QDS is for the fabrication of high efficiency solar cells says Yamaguchi.
Step by step we have pushed the limits of'self-organization'based growth of QDS and succeeded in producing highly ordered ultra-high densities of QDS.
The realization of an unprecedented QDS density of 5 x 1011 cm-2 in 2011 was one of the major milestones in the development of'self-organization'based semiconducting QDS for solar cells by Yamaguchi
The resulting external quantum efficiency of these solar cell structures in the 900 to 1150 nm wavelength range was higher than devices with the QD layer.
Theoretical studies suggest QDS solar cells could yield conversion efficiencies over 50%explains Yamaguchi. This is a very challenging target
but we hope that our innovative approach will be an effective means of producing such QD based high performance solar cells.
Resonant energy transfer from quantum dots to graphene More information: Edes Saputra Jun Ohta Naoki Kakuda and Koichi Yamaguchi Self-Formation of In-Plane Ultrahigh-Density Inas Quantum dots on Gaassb/Gaas (001) Appl.
efficiency of intermediate-band solar cells J. Appl. Phys. 112 124515 (2012
#Magnetic field opens and closes nanovesicle Chemists and physicists of Radboud University managed to open and close nanovesicles using a magnet.
The nanoprobes are initially pink due to surface plasmonic effects involving ripples of electric charge. When analyzed if the probes do not bind to the DNA fragments they aggregate
#Researchers uncover properties in nanocomposite oxide ceramics for reactor fuel Nanocomposite oxide ceramics have potential uses as ferroelectrics fast ion conductors
In the context of nuclear energy composites have been proposed for the fuel itself as a way for example to improve the basic properties of the material such as the thermal conductivity.
It is the thermal conductivity that dictates how efficiently energy can be extracted from the fuel. Composites have also been created to store the by-products of the nuclear energy cycle nuclear waste where the different components of the composite can each store a different part of the waste.
However composites have much broader applications. The interfaces provide regions of unique electronic and ionic properties
and have been studied for enhance conductivity for applications related to batteries and fuel cells. Using simulations that explicitly account for the position of each atom within the material the Los alamos research team examined the interface between Srtio3
Reactor fuel behavior better understood with phonon insights More information: The research is described in a paper out this week in Nature Communications Termination chemistry-driven dislocation structure at Srtio3/Mgo heterointerfaces s
and solar cells crafted with inorganic compound semiconductor micro-rods are moving one step closer to reality thanks to graphene and the work of a team of researchers in Korea.
With nanoparticles, they produced temperature-sensitive devices that transmit electrical energy to the system but do not cause overheating.
electric power is applied and removed for some time, whith the purpose of determining how long it takes to return to its original condition i
For comparison a 10w light bulb emits 1020 photons every second. The team's ultimate goal is to transport only one photon in a cycle
"Many researchers are looking to inorganic materials for new sources of energy, "said Elena Rozhkova, chemist at Argonne's Center for Nanoscale Materials, a DOE Office of Science (Office of Basic energy Sciences) User Facility."
"Our goal is to learn from the natural world and use its materials as building blocks for innovation."
"For Rozhkova, this particular building block is inspired by the function of an ancient protein known to turn light into energy.
and pump protons through a membrane, creating a form of chemical energy. They also know that water can be split into oxygen
Graphene is a super strong, super light, near totally transparent sheet of carbon atoms and one of the best conductors of electricity ever discovered.
can create new sources of clean energy. Her team's discovery may provide future consumers a biologically-inspired alternative to gasoline."
"Working in the basic energy sciences, we were able to demonstrate an energy-rich biologically-inspired alternative to gas."
"This research,"Photoinduced Electron Transfer pathways in Hydrogen-Evolving Reduced graphene oxide-Boosted Hybrid Nano-Bio Catalyst,
Johnson said the company's graphene supercapacitors are reaching the energy density of lithium-ion batteries without a similar energy fade over time.
Our graphene-based supercapacitors charge in just a fraction of the time needed to charge lithium-ion batteries.
and conduct both heat and electricity. Last year the Rice group created films of overlapping nanoribbons
The material would replace a bulky and energy-hungry metal oxide framework. The graphene-infused paint worked well Tour said
physical limitations like energy consumption and heat dissipation are too significant. Now, using a quantum material called a correlated oxide,
or conducts electricity. Doping typically effects this change by increasing the number of available electrons,
The Harvard team manipulated the band gap, the energy barrier to electron flow.""By a certain choice of dopantsn this case, hydrogen or lithiume can widen
The traditional method changes the energy level to meet the target; the new method moves the target itself.
And, in the absence of power, the material remembers its present staten important feature for energy efficiency."
#Study sheds new light on why batteries go bad A comprehensive look at how tiny particles in a lithium ion battery electrode behave shows that rapid-charging the battery
The results challenge the prevailing view that supercharging batteries is always harder on battery electrodes than charging at slower rates according to researchers from Stanford university and the Stanford Institute for Materials & Energy Sciences (SIMES) at the Department of energy's SLAC National Accelerator Laboratory.
or change the way batteries are charged to promote more uniform charging and discharging and extend battery life.
The fine detail of what happens in an electrode during charging and discharging is just one of many factors that determine battery life
but it's one that until this study was understood not adequately said William Chueh of SIMES an assistant professor at Stanford's Department of Materials science and engineering and senior author of the study.
We have found a new way to think about battery degradation. The results he said can be applied directly to many oxide
and graphite electrodes used in today's commercial lithium ion batteries and in about half of those under development.
One important source of battery wear and tear is the swelling and shrinking of the negative and positive electrodes as they absorb
and release ions from the electrolyte during charging and discharging. For this study scientists looked at a positive electrode made of billions of nanoparticles of lithium iron phosphate.
and get ruined degrading the battery's performance. Previous studies produced conflicting views of how the nanoparticles behaved.
To probe further researchers made small coin cell batteries charged them with different levels of current for various periods of time quickly took them apart
But when the batteries discharged an interesting thing happened: As the discharge rate increased above a certain threshold more and more particles started to absorb ions simultaneously switching to a more uniform and less damaging mode.
and discharging while maintaining long battery life. The next step Li said is to run the battery electrodes through hundreds to thousands of cycles to mimic real-world performance.
The scientists also hope to take snapshots of the battery while it's charging and discharging rather than stopping the process and taking it apart.
This should yield a more realistic view and can be done at synchrotrons such as ALS or SLAC's Stanford Synchrotron radiation Lightsource also a DOE Office of Science User Facility.
Live from inside a battery: Researchers observe the phenomenon of'lithium plating'during the charging process More information:
The as-fabricated N-ACNT/G sandwiches described in the journal Advanced Materials on Sep 17 2014 demonstrated high-rate performances in lithium-sulfur (Li-S) batteries.
One of the most promising candidates for next-generation power sources Li-S battery is with very high theoretical energy density of 2600 Wh kg-1 natural abundance
and rate performances of Li-S batteries for practical application with the N-ACNT/G hybrids as cathode materials. said Prof.
The 3d interconnected mesoporous space improves the penetration and diffusion of electrolytes. Additionally the nitrogen-modified interfaces give rise to enhanced interfacial affinity for efficient confinement and utilization of sulfur and polysulfides.
Facile Catalytic Growth on Bifunctional Natural Catalysts and Their Applications as Scaffolds for High-Rate Lithium-Sulfur Batteries.
the method could be particularly useful for applications in optics, energy efficiency, and biomedicine. For example, it could be used to reproduce complex structures such as bone,
an advancement that could enable electronic devices to function with very little energy. The process involves passing electrons through a quantum well to cool them
The team details its research in"Energy-filtered cold electron transport at room temperature, "which is published in Nature Communications on Wednesday, Sept. 10."
"Dr. Koh and his research team are developing real-world solutions to a critical global challenge of utilizing the energy efficiently
these research findings could potentially reduce energy consumption of electronic devices by more than 10 times compared to the present technology,
Batteries weigh a lot, and less power consumption means reducing the battery weight of electronic equipment that soldiers are carrying,
which will enhance their combat capability. Other potential military applications include electronics for remote sensors, unmanned aerial vehicles and high-capacity computing in remote operations.
The most important challenge of this future research is to keep the electron from gaining energy as it travels across device components.
This would require research into how energy-gaining pathways could be blocked effectively
#Molecular self-assembly controls graphene-edge configuration A research team headed by Prof. Patrick Han and Prof.
It turns out that by adding fluorine Liu said we're changing the energy corrugation landscape of the graphene.
but the physical changes in height paled in comparison to the changes of local energy each fluorine atom produced.
but also how much energy is in their bonds. Each fluorine atom has so much electronic charge that you get tall peaks
and electricity it is transparent harder than diamond and extremely strong. But in order to use it to construct electronic switches a material must not only be an outstanding conductor it should also be switchable between on and off states.
and collaborators at Rensselaer Polytechnic institute The latter has a direct impact on the power yield of solar cells.
and his colleagues describe a possible use of graphene strips for instance in solar cells. Ruffieux and his team have noticed that particularly narrow graphene nanoribbons absorb visible light exceptionally well
and are therefore highly suitable for use as the absorber layer in organic solar cells. Compared to normal graphene
and electricity better than any other known materialas potential industrial uses that include flexible electronic displays, high-speed computing, stronger wind turbine blades,
and more-efficient solar cells, to name just a few under development. In the decade since Nobel laureates Konstantin Novoselov and Andre Geim proved the remarkable electronic and mechanical properties of graphene
but instead retain that energy. The concept behind the detector is simple says University of Maryland Physics Professor Dennis Drew.
which heat up but don't lose their energy easily. So they remain hot while the carbon atomic lattice remains cold.
In digital electronics these transistors control the flow of electricity throughout an integrated circuit and allow for amplification and switching.
#Atomically thin material opens door for integrated nanophotonic circuits A new combination of materials can efficiently guide electricity
Typically about a third of the remaining energy would be lost for every few microns (millionths of a meter) the plasmons traveled along the wire explained Kenneth Goodfellow a graduate student at Rochester's Institute of Optics
It was surprising to see that enough energy was left after the round-trip said Goodfellow.
As Mos2 is reduced to thinner and thinner layers the transfer of energy between electrons and photons becomes more efficient.
The key to Mos2's desirable photonic properties is in the structure of its energy band gap.
which allows electrons to easily move between energy bands by releasing photons. Graphene is inefficient at light emission
at this time organic photovoltaic devices are hindered by low efficiency relative to commercial solar cells in part because quantifying their electrical properties has proven challenging.
"This measurement breakthrough should allow us to more rapidly optimize solar cells,"Richter states.""We're able to look at what happens electronically throughout the entire device.
The larger the difference between the charge lifetime and device transit time greatly improves the likelihood that a photovoltaic device will be a more efficient source of electrical power."
But, when the device does not perform as a"textbook"or"ideal"solar cell then the picture of
Photovoltaic devices, also known as solar cells, produce electrical power when exposed to light, and that technology has enabled a fast-growing industry.
and ultimately more closely connect materials properties with processing methods and solar cell performance.""And since the physical process governing organic photovoltaics is very similar to other organic semiconductors (organic light-emitting diodes, for example,
which are prevalent in electronic displays), future applications of this technique to other industries appears straight forward."
Understanding how materials grow at the nanoscale level helps scientists tailor them for everything from batteries to solar cells.
which for example the next generation of batteries will operate. Engineering new materials to address today's societal problems is a complex and demanding agenda Zaluzec said.
but immensely powerful batteries) and an array of new materials that could make many of today's common metals and polymers redundant.
The graphene gel provides the same functionality as porous carbon a material currently sourced from coconut husks for use in supercapacitors and other energy conversion and storage technologies but with vastly enhanced performance.
or LEDS, and solar technologies.""Heterojunctions are fundamental elements of electronic and photonic devices, "said senior author Xiaodong Xu, a UW assistant professor of materials science and engineering and of physics."
and solar cells to be developed for highly integrated electronic and optical circuits within a single atomic plane."
which is encouraging for optoelectric and photonic applications like solar cells c
#Competition for graphene: Researchers demonstrate ultrafast charge transfer in new family of 2-D semiconductors A new argument has just been added to the growing case for graphene being bumped off its pedestal as the next big thing in the high-tech world by the two-dimensional semiconductors
comparable to the fastest times recorded for organic photovoltaics.""We've demonstrated, for the first time, efficient charge transfer in MX2 heterostructures through combined photoluminescence mapping and transient absorption measurements,"says Feng Wang, a condensed matter physicist with Berkeley Lab's Materials sciences Division
but, unlike graphene, they have natural energy bandgaps. This facilitates their application in transistors and other electronic devices because
who is also an investigator with the Kavli Energy Nanosciences Institute (Kavli-ENSI).""For example, the combination of Mos2 and WS2 forms a type-II semiconductor that enables fast charge separation.
The separation of photoexcited electrons and holes is essential for driving an electrical current in a photodetector or solar cell."
not only for photonics and optoelectronics, but also for photovoltaics.""MX2 semiconductors have extremely strong optical absorption properties
#Conductive nanofiber networks for flexible unbreakable and transparent electrodes Transparent conductors are required as electrodes in optoelectronic devices, such as touch panel screens, liquid crystal displays, and solar cells.
Examples of applications are large displays, large interactive touch screens, photovoltaic solar panels, light-emitting diode panels, smart phones,
#Scientists fabricate defect-free graphene set record reversible capacity for Co3o4 anode in Li-ion batteries Graphene has already been demonstrated to be useful in Li-ion batteries,
and size-tunable for battery applications has remained so far elusive. Now in a new study, scientists have developed a method to fabricate defect-free graphene (df-G) without any trace of structural damage.
Wrapping a large sheet of negatively charged df-G around a positively charged Co3o4 creates a very promising anode for high-performance Li-ion batteries.
including batteries, fuel cells, and capacitors r
#Copper shines as flexible conductor Bend them, stretch them, twist them, fold them: modern materials that are light,
"It has been shown that nanoparticles with resonant properties can be uncoupled over subwavelength distances so their electromagnetic fields have minimal interaction,
and transfer electricity to a variety of solid surfaces. Today a team led by scientists at USC has turned the study of these bacterial nanowires on its head discovering that the key features in question are not pili as previously believed
and others at the University of Massachusetts Amherst today report a breakthrough technique for controlling molecular assembly of nanoparticles over multiple length scales that should allow faster cheaper more ecologically friendly manufacture of organic photovoltaics and other electronic devices.
Materials chemist Paul Lahti co-director with Thomas Russell of UMASS Amherst's Energy Frontiers Research center (EFRC) supported by the U s. Department of energy says One of the big implications of this work
is that it goes well beyond organic photovoltaics or solar cells where this advance is being applied right now.
Looking at the bigger picture this technique offers a very promising flexible and ecologically friendly new approach to assembling materials to make device structures.
The new method should reduce the time nano manufacturing firms spend in trial-and-error searches for materials to make electronic devices such as solar cells organic transistors and organic light-emitting diodes.
For photovoltaics Venkataraman points out The next thing is to make devices with other polymers coming along to increase power conversion efficiency
He suggests that reaching 5 percent power conversion efficiency would justify the investment for making small flexible solar panels to power devices such as smart phones.
and all 307 million United states users switched from batteries to flexible solar it could save more than 1500 megawatts per year.
That's nearly the output of a nuclear power station Venkataraman says and it's more dramatic
Doctoral student and first author Tim Gehan says that organic solar cells made in this way can be semitransparent as well so you could replace tinted windows in a skyscraper
and have them all producing electricity during the day when it's needed. And processing is much cheaper and cleaner with our cells than in traditional methods.
Scientists develop pioneering new spray-on solar cells More information: Nano Letters pubs. acs. org/doi/pdf/10.1021/nl502209 9
Her team now plans to use the nanorods as seeds themselves to synthesize nanoparticles comprised of a goldopper core surrounded by a shell of another material, such as platinum, for energy applications
and rock music improves the performance of solar cells, in research published with Imperial College London. Developing this research further,
or stretched creates a voltage by converting energy from motion into electrical energy, in the form of nanorods.
or do away with batteries completely by tapping into the stray energy that is all around us is an exciting concept.
and form the basis of countless electronic devices such as memory chips photovoltaic cells logic gates and sensors. An interesting alternative to inorganic TFTS (silicon) is organic TFTS (OTFTS)
#New graphene framework bridges gap between traditional capacitors batteries Researchers at the California Nanosystems Institute (CNSI) at UCLA have set the stage for a watershed in mobile energy storage by using a special graphene material
to significantly boost the energy density of electrochemical capacitors, putting them on a par with lead acid batteries.
The material, called a holey graphene framework, has perforated a three-dimensional structure characterized by tiny holes;
it not only increases energy density (the amount of energy stored and ready for use) but allows electrochemical capacitors to maintain their high power density (the amount of power per unit of mass or volume), according to Xiangfeng Duan,
Compared with traditional batteries, ECS typically have superior power density and cycle lifehe number of complete chargeischarge cycles an energy source can support before it decreases to 80 percent of its original capacity
and is considered"worn out.""But they have had energy density of at least one order of magnitude below batteries. Because the main component of an EC is its electrode material,
which is responsible for the EC's overall performance, recent research has focused on efficient new materials that are able to increase energy density without sacrificing power density or cycle life.
A high-performance EC electrode must have high electrical conductivity, a high ion-accessible surface area, a high ionic transport rate and high electrochemical stability.
Current state-of-the-art ECS generally use porous activated carbon electrodes with energy densities much lower than lead acid batteries to 5 watt hours per kilogram vs. 25 to 35 watt hours per kilogram (5
and ions and enabling the highest gravimetric energy densities of 127 watt hours per kilogram and volumetric energy density of 90 watt hours per liter.
Furthermore, the team has shown that a fully packaged EC exhibits unparalleled energy densities of 35 watt hours per kilogram (49 watt hours per liter) bout five to 10 times higher than current commercial supercapacitors and on a par
with acid batteries.""The holey grahene EC bridges the energy density gap between traditional capacitors and batteries, yet with vastly higher power density,"Duan said."
"It creates exciting opportunities for mobile power supplies for many applications from cell phones to electric vehicles. v
#Stronger better solar cells: Graphene research on the cusp of new energy capabilities (Phys. org) There remains a lot to learn on the frontiers of solar power research particularly
when it comes to new advanced materials which could change how we harness energy. Under the guidance of Canada Research Chair in Materials science with Synchrotron radiation Dr. Alexander Moewes University of Saskatchewan researcher Adrian Hunt spent his Phd investigating graphene oxide a cutting-edge material that he hopes will shape the future
of technology. To understand graphene oxide it is best to start with pure graphene which is a single-layer sheet of carbon atoms in a honeycomb lattice that was made first in 2004 by Andre Geim
All of this makes graphene a great candidate for solar cells. In particular its transparency and conductivity mean that it solves two problems of solar cells:
first light needs a good conductor in order to get converted into usable energy; secondly the cell also has to be transparent for light to get through.
Most solar cells on the market use indium tin oxide with a nonconductive glass protective layer to meet their needs.
Indium is extremely rare so it is becoming more expensive all the time. It's the factor that will keep solar cells expensive in the future
whereas graphene could be very cheap. Carbon is said abundant Hunt. Although graphene is a great conductor it is not very good at collecting the electrical current produced inside the solar cell
which is why researchers like Hunt are investigating ways to modify graphene to make it more useful.
Whether or not it will solve the solar panel problem is yet to be seen and researchers in the field are building up their understanding of how the new material works.
It's a pitfall that could be important to understand in the development of long-lasting solar cells where sun could provide risky heat into the equation.
#Used-cigarette butts offer energy storage solution A group of scientists from South korea have converted used-cigarette butts into a high-performing material that could be integrated into computers handheld devices electrical vehicles and wind turbines to store energy.
which simultaneously offers a green solution to meeting the energy demands of society. Numerous countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used-cigarette filters that are disposed of into the environment each yearur method is just one way of achieving this.
Scientists around the world are currently working towards improving the characteristics of supercapacitorsuch as energy density power density
and tested in a three-electrode system to see how well the material could adsorb electrolyte ions (charge) and then release electrolyte ions (discharge).
The material stored a higher amount of electrical energy than commercially available carbon and also had a higher amount of storage compared to graphene
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