or microfluidic devices or solar panels that could automatically clean themselves of dust and grit. Most surfaces are passive says Kripa Varanasi an associate professor of mechanical engineering at MIT
For example solar panels and the mirrors used in solar-concentrating systems can quickly lose a significant percentage of their efficiency
The issue of dust basically makes the use of solar panels to be less efficient than in North america or Europe.
At the time he was working on various photonics projects lasers solar cells and optical fiber that all involved a phenomenon called resonant coupling.
or in improving the efficiency of solar cells. While this analysis still leaves open questions about the precise structure of eumelanin molecules, Buehler says,
#Getting more electricity out of solar cells When sunlight shines on today solar cells, much of the incoming energy is given off as waste heat rather than electrical current.
yielding new design guidelines for using those special materials to make high-efficiency solar cells. The results are reported in the journal Nature Chemistry by MIT alumni Shane R. Yost and Jiye Lee,
However, achieving it in a functioning solar cell has proved difficult and the exact mechanism involved has become the subject of intense controversy in the field.
In 2013, they reported making the first solar cell that gives off extra electrons from high-energy visible light,
According to their estimates, applying their technology as an inexpensive coating on silicon solar cells could increase efficiency by as much as 25 percent.
The results also provide practical guidelines for designing solar cells with these materials. They show that molecular packing is important in defining the rate of fission but only to a point.
whose integrated chip restores lost power to partially shaded solar panels achieving double the energy capture improvement of similar technologies won big on Monday night at the seventh annual MIT Clean energy Prize (CEP) competition.
Solar panels on residential rooftops that are shaded partially by clouds or trees sacrifice as much as 30 percent of their energy potential over a year.
Unified Solar technology, for the first time, integrates an entire power balance circuit onto a low-cost chip that can be integrated into a solar panel to regain that lost energy. n the real world,
Existing solutions for partially shaded solar panels optimize power at the panel level. But these bulky oxesrely on costly energy storage components
you learn a lot about properties of solar cells that people often ignored as parasitic components. People wanted to get rid of them,
but we found a way to leverage them. o one has thought ever of using the solar cell as an energy storage itself,
and routing device that plugs into solar panels to power electronic devices, enabling a pay-as-you-go electricity system for people off the grid.
which turns solar cells into cogeneration systems. Sun exposure to solar panels produces about 0. 5 percent of wasted heat per Degree celsius increase.
Thermovolt modified solar cell captures that wasted energy and uses it to heat water for homes.
The two other audience choice awards went to REECYCLE, which reclaims rare earth elements from recycled electronics to create other resources,
#Excitons observed in action for the first time A quasiparticle called an exciton responsible for the transfer of energy within devices such as solar cells LEDS
For example in a solar cell an incoming photon may strike an electron kicking it to a higher energy level.
for other uses such as solar cells it is essential to minimize the trapping. The new technique should allow researchers to determine which factors are most important in increasing
which is the defining characteristic of most materials for low-cost solar cells and LEDS Baldo says.
That light emission can then be harnessed using a photovoltaic cell tuned to make maximum use of that color of light.
which could one day be used to design more complex devices such as solar cells self-healing materials
and solar cells Lu says. The researchers are interested also in coating the biofilms with enzymes that catalyze the breakdown of cellulose
Supercharged photosynthesis The idea for nanobionic plants grew out of a project in Strano lab to build self-repairing solar cells modeled on plant cells.
As a next step, the researchers wanted to try enhancing the photosynthetic function of chloroplasts isolated from plants, for possible use in solar cells.
even at the extremely low power levels characteristic of tiny solar cells. Previous ultralow-power converters that used the same approach had efficiencies of only 40 or 50 percent.
Where most of its ultralow-power predecessors could use a solar cell to either charge a battery
Ups and downs The circuit chief function is to regulate the voltages between the solar cell, the battery,
and falls depends on the voltage generated by the solar cell, which is highly variable. So the timing of the switch throws has to vary, too.
whose selection is determined by the solar cell voltage. Once again, when the capacitor fills, the switches in the inductor path are flipped. n this technology space,
#New technique helps probe performance of organic solar cell materials A research team led by North carolina State university has developed a new technique for determining the role that a material's structure has on the efficiency of organic solar cells
There have been a lot of studies looking at the efficiency of organic solar cells but the energy conversion process involves multiple steps
Broadly speaking organic solar cells convert light into electric current in four steps. First the cell absorbs sunlight which excites electrons in the active layer of the cell.
In previous organic solar cell research there was ambiguity about whether differences in efficiency were due to dissociation or charge collection#because there was no clear method for distinguishing between the two.
so that it runs parallel to the long axis of organic solar cell molecules it will be absorbed; but if the light runs perpendicular to the molecules it passes right through it.
The researchers created highly organized nanostructures within a portion of the active layer of an organic solar cell meaning that the molecules in that portion all ran the same way.
or just the disorganized section#even though they were on the same active layer of the same solar cell.
and nanostructure features are needed to advance organic solar cell technology. Explore further: Hybrid materials could smash the solar efficiency ceiling More information:
Awartani O. Kudenov M. W. Kline R. J. and O'connor B. T. 2015) In-Plane Alignment in Organic solar cells to Probe the Morphological Dependence of Charge Recombination.
#Researchers create novel nanobowl optical concentrator for organic solar cell Geometrical light trapping is a simple and promising strategy to largely improve the optical absorption and efficiency of solar cells.
Meanwhile light trapping by nano-textured substrate is an appealing strategy to improve solar cell efficiency.
The novel nanobowl optical concentrator developed by Professor Zhiyong Fan can largely enhance the optical absorption in the active layer of organic solar cell
In addition they have investigated the effect of geometry of nanobowl on the solar cell performance and three types of nanobowl with pitch of 1000 nm 1200 nm and 1500 nm were studied.
Solar cells based on nanobowl with pitch of 1000 nm exhibited the best photon absorption in photoactive layer leading to the highest short-circuit current density of 9. 41 ma cm-2 among all nanobowl substrates.
With open-circuit voltage of 0. 573 V and fill factor of 57.9%this nanobowl solar cell achieved a solar energy conversion efficiency of 3. 12
the researchers tested a number of molecules that are used also within organic solar cell research at Chalmers.
whether the crystalline structure of the materials is mismatched-lowering the manufacturing cost for a wide variety of semiconductor devices such as solar cells lasers and LEDS.
For example in photonic devices like solar cells lasers and LEDS the junction is where photons are converted into electrons or vice versa.
This manufacturing cost is a major reason why semiconductor devices such as solar cells lasers and LEDS remain very expensive.
#Lengthening the life of high capacity silicon electrodes in rechargeable lithium batteries A new study will help researchers create longer-lasting higher-capacity lithium rechargeable batteries
In a study published in the journal ACS Nano researchers showed how a coating that makes high capacity silicon electrodes more durable could lead to a replacement for lower-capacity graphite electrodes.
Understanding how the coating works gives us an indication of the direction we need to move in to overcome the problems with silicon electrodes said materials scientist Chongmin Wang of the Department of energy's Pacific Northwest National Laboratory.
Silicon electrodes aren't very durable#after a few dozen recharges they can no longer hold electricity. That's partly due to how silicon takes up lithium#like a sponge.
and thoroughly#an improvement over earlier silicon electrodes#but only partly alleviates the fracturing problem. Last year materials scientist Chunmei Ban and her colleagues at the National Renewable energy Laboratory in Golden Colorado and the University of Colorado Boulder found that they could cover silicon nanoparticles with a rubberlike coating made from aluminum glycerol.
Ban's group#which developed the coating for silicon electrodes called alucone and is currently the only group that can create alucone-coated silicon particles#took high magnification images of the particles in an electron microscope.
and inorganic-based energy devices such as battery solar cell and self-powered devices that require high temperature processes s
#New nanocomposites for aerospace and automotive industries The Center for Research in Advanced Materials (CIMAV) has developed reinforced graphite nanoplatelets seeking to improve the performance of solar cell materials.
#Graphene/nanotube hybrid benefits flexible solar cells Rice university scientists have invented a novel cathode that may make cheap, flexible dye-sensitized solar cells practical.
The discovery was reported online in the Royal Society of Chemistry's Journal of Materials Chemistry A. Dye-sensitized solar cells have been in development
While they are not nearly as efficient as silicon-based solar cells in collecting sunlight and transforming it into electricity,
dye-sensitized solar cells have advantages for many applications, according to co-lead author Pei Dong, a postdoctoral researcher in Lou's lab."The first is that they're low-cost,
The hybrid material solves two issues that have held back commercial application of dye-sensitized solar cells,
Lou's lab built and tested solar cells with nanotube forests of varying lengths The shortest,
Tests found that solar cells made from the longest nanotubes produced the best results and topped out at nearly 18 milliamps of current per square centimeter
The new dye-sensitized solar cells were as much as 20 percent better at converting sunlight into power,
This approach to growing nanomaterials will improve the efficiency of various devices including solar cells and fuel cells.
These semiconducting nanowires could also replace thin films that cover today's solar panels. Current panels can process only 20 percent of the solar energy they take in.
The new kind of nanotubes also could lead to flexible solar panels that can be rolled up and stored or even"painted"on clothing such as a jacket,
and reduce the cost of solar cells and increase the capacity and reduce the charging time of batteries he says.
The resulting batteries and solar cells are also mechanically flexible and thus can be integrated with flexible electronics.
Breakthrough for carbon nanotube solar cell l
#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene
The ability to mold inorganic nanoparticles out of materials such as gold and silver in precisely designed 3-D shapes is a significant breakthrough that has the potential to advance laser technology microscopy solar cells electronics environmental testing
and replace them with synthetic components to create a new generation of solar cells. Professor Evans concludes:"
#Blades of grass inspire advance in organic solar cells Using a biomimicking analog of one of nature's most efficient light-harvesting structures blades of grass an international research team led by Alejandro Briseno of the University of Massachusetts Amherst
or discontinuous pathways that pose a serious drawback when using blended systems known as bulk heterojunction donor-acceptor or positive-negative (p-n) junctions for harvesting energy in organic solar cells.
He says This work is a major advancement in the field of organic solar cells because we have developed
The breakthrough in morphology control should have widespread use in solar cells batteries and vertical transistors he adds.
For decades scientists and engineers have placed great effort in trying to control the morphology of p-n junction interfaces in organic solar cells.
We envision that our nanopillar solar cells will appeal to low-end energy applications such as gadgets toys sensors and short lifetime disposable devices s
#Nanoengineering enhances charge transport promises more efficient future solar cells Solar cells based on semiconducting composite plastics and carbon nanotubes is one of the most promising novel technology for producing inexpensive printed solar cells.
Physicists at Umeå University have discovered that one can reduce the number of carbon nanotubes in the device by more than 100 times
Carbon nanotubes are more and more attractive for use in solar cells as a replacement for silicon. They can be mixed in a semiconducting polymer
and deposited from solution by simple and inexpensive methods to form thin and flexible solar cells.
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.
#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
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,
#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.
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
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.
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.
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.
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 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
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.
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,
Understanding how materials grow at the nanoscale level helps scientists tailor them for everything from batteries to solar cells.
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
The separation of photoexcited electrons and holes is essential for driving an electrical current in a photodetector or solar cell."
#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,
or solar cells where this advance is being applied right now. Looking at the bigger picture this technique offers a very promising flexible
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.
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.
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
Scientists develop pioneering new spray-on solar cells More information: Nano Letters pubs. acs. org/doi/pdf/10.1021/nl502209 9
and rock music improves the performance of solar cells, in research published with Imperial College London. Developing this research further,
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)
#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
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.
It's the factor that will keep solar cells expensive in the future whereas graphene could be very cheap.
Although graphene is a great conductor it is not very good at collecting the electrical current produced inside the solar cell
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.
#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,
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.
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.
the solar cell will not work.""Eventually, this feat was accomplished by heating both layers in vacuum and stacking it in ambient atmosphere.
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
"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
#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
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.
Thus far, for instance, materials such as chalk, cement, solar cells and fossils have been studied in collaboration with various research institutions n
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.
including copper zinc tin sulfide and copper indium diselenide for solar cells. New Oregon jobs and businesses are already evolving from this work.
#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.
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
New breed of solar cells: Quantum dot photovoltaics set new record for efficiency in such devices More information:
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.
#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
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.
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
Many approaches to creating low-cost large-area flexible and lightweight solar cells suffer from serious limitations such as short operating lifetimes
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.
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.
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