Scientists purify copper nanowires – Woot – Woot! Why this Discovery will Matter to YOU – Apple and Others


An illustration of the separation process from a mixture of various copper nanocrystal shapes (two tubes to the left) to pure nanowires and nanoparticles (two tubes to the right). Credit: Lawrence Livermore National Laboratory



Cell phones and Apple watches could last a little longer due to a new method to create copper nanowires.

A team of Lawrence Livermore National Laboratory (LLNL) scientists have created a new method to purify copper nanowires with a near-100 percent yield. These nanowires are often used in nanoelectronic applications.




The research, which appears in the online edition of Chemical Communications and on the cover of the hardcopy issue, shows how the method can yield large quantities of long, uniform, high-purity copper nanowires. 
High-purity copper nanowires meet the requirements of nanoelectronic applications as well as provide an avenue for purifying industrial-scale synthesis of copper nanowires, a key step for commercialization and application.

Metal nanowires (NWs) hold promise for commercial applications such as flexible displays, solar cells, catalysts and heat dissipators.

The most common approach to create nanowires not only yield nanowires but also other low-aspect ratio shapes such as nanoparticles (NPs) and nanorods. These undesired byproducts are almost always produced due to difficulties in controlling the non-instantaneous nucleation of the seed particles as well as seed types, which causes the particles to grow in multiple pathways.

“We created the purest form of copper nanowires with no byproducts that would affect the shape and purity of the nanowires,” said LLNL’s Fang Qian, lead author of the paper.
The team demonstrated that copper nanowires, synthesized at a liter-scale, can be purified to near 100 percent yield from their nanoparticle side-products with a few simple steps.

Functional nanomaterials are notoriously difficult to produce in large volumes with highly controlled composition, shapes and sizes. This difficulty has limited adoption of nanomaterials in many manufacturing technologies.




“This work is important because it enables production of large quantities of copper nanomaterials with a very facile and elegant approach to rapidly separate nanowires from nanoparticles with extremely high efficiency,” said Eric Duoss, a principal investigator on the project. “We envision employing these purified nanomaterials for a wide variety of novel fabrication approaches, including additive manufacturing.”

The key to success is the use of a hydrophobic surfactant in aqueous solution, together with an immiscible water organic solvent system to create a hydrophobic-distinct interface, allowing nanowires to crossover spontaneously due to their different crystal structure and total surface area from those of nanoparticles.

“The principles developed from this particular case of copper nanowires may be applied to a variety of nanowire applications,” Qian said. “This purification method will open up new possibilities in producing high quality nanomaterials with low cost and in large quantities.”
Other Livermore researchers include: Pui Ching Lan, Tammy Olson, Cheng Zhu and Christopher Spadaccini.

“We also are developing high surface area foams as well as printable inks for additive manufacturing processes, such as direct-ink writing using the NWs,” said LLNL’s Yong Han, a corresponding author of the paper.

 Explore further: A novel method of making high-quality vertical nanowires

More information: Fang Qian et al. Multiphase separation of copper nanowires, Chem. Commun. (2016). DOI: 10.1039/C6CC06228H 

Journal reference: Chemical Communications  

Provided by: Lawrence Livermore National Laboratory

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Nano-Crystal (Quantum Dots) Boosted System Shows Doubled Light-Harvesting Ability


1-ACS Solar Band Gap nl-2014-03322a_0005Publication Date (Web): October 16, 2014

Conventional solar cells exhibit limited efficiencies in part due to their inability to absorb the entire solar spectrum. Sub-band-gap photons are typically lost but could be captured if a material that performs up-conversion, which shifts photon energies higher, is coupled to the device.

Recently, molecular chromophores that undergo triplet–triplet annihilation (TTA) have shown promise for efficient up-conversion at low irradiance, suitable for some types of solar cells. However, the molecular systems that have shown the highest up-conversion efficiency to date are ill suited to broadband light harvesting, reducing their applicability.

1-ACS Solar Band Gap nl-2014-03322a_0005

Here we overcome this limitation by combining an organic TTA system with highly fluorescent CdSe semiconductor nanocrystals. Because of their broadband absorption and spectrally narrow, size-tunable fluorescence, the nanocrystals absorb the radiation lost by the TTA chromophores, returning this energy to the up-converter. The resulting nanocrystal-boosted system shows a doubled light-harvesting ability, which allows a green-to-blue conversion efficiency of ∼12.5% under 0.5 suns of incoherent excitation. This record efficiency at subsolar irradiance demonstrates that boosting the TTA by light-emitting nanocrystals can potentially provide a general route for up-conversion for different photovoltaic and photocatalytic applications.

Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, 20125 Milano, Italy
Optical Materials Engineering Laboratory, ETH Zurich, 8092 Zurich, Switzerland
Nano Lett., Article ASAP
DOI: 10.1021/nl503322a
Publication Date (Web): October 16, 2014
Copyright © 2014 American Chemical Society

Stanford’s GCEP awards $10.5 million for Research on Renewable Energy


 

Nano fuel cells c2cs35307e-f1The Global Climate and Energy Project (GCEP) at Stanford University has awarded $10.5 million for seven research projects designed to advance a broad range of renewable energy technologies. The funding will be shared by six Stanford research teams and an international group from the United States and Europe.

“The seven projects funded by GCEP could spark discoveries that lead to dramatic improvements in energy storage, solar cells and renewable biofuels,” said GCEP Director Sally Benson, a professor of energy resources engineering at Stanford. “I’m delighted to add that many of the scientists who received funding for these innovative projects will be featured speakers at our 2014 GCEP Research Symposium in October.”

The seven awards bring the total number of GCEP-supported research programs to 117 since the project’s launch in 2002. In total, GCEP has awarded approximately $161 million to researchers at Stanford and 40 other institutions worldwide.

“These awards demonstrate GCEP’s continued commitment to advancing cutting- edge research in energy,” said GCEP management committee member Steven Freilich, director of materials science at DuPont Central Research & Development. “As a science company, DuPont believes that collaboration enhances our power to innovate. Programs like GCEP help build the great working relationships between scientists and engineers at universities, companies and government institutions that are required to develop innovative solutions for people everywhere.”

The following Stanford faculty members received funding for advanced research on photovoltaics, battery technologies and new catalysts for sustainable fuels:

Self-healing polymers for high energy density lithium-ion batteries. The goal is to develop high-energy, durable lithium-ion batteries for electric vehicles by improving the cycle life of the battery electrodes. Researchers will design self-healing polymers that can stretch to accommodate large volume changes in the battery during charge and discharge. Investigators: Zhenan Bao, Chemical Engineering; Yi Cui, Materials Science and Engineering.Battery Secret untitled

Photo-electrochemically rechargeable zinc-air batteries. The zinc-air battery is a promising technology that has high energy density but limited power density. The research team will develop a photo-electrochemical battery with a stable zinc electrode capable of generating electricity using sunlight and air. Investigator: Hongjie Dai, Chemistry.

Novel inorganic-organic perovskites for photovoltaics. The mineral perovskite is a promising, low-cost material for enhancing the efficiency of silicon solar cells. The goal of this project is to develop a hybrid perovskite-silicon solar cell that significantly improves the light-to-energy conversion efficiency of conventional cells. Investigators: Michael McGehee, Materials Science and Engineering; Hemamala Karunadasa, Chemistry.

ElectrodeBarrierLight trapping in high‐efficiency, low‐cost silicon solar cells. This work aims to develop a new technique for trapping sunlight in thin-film silicon solar cells. Silicon and other materials will be engineered into nanosize spheres, domes and wires that promote light absorption and improve the overall efficiency of the solar cell. Investigator: Mark Brongersma, Materials Science and Engineering.

Maximizing solar-to-fuel conversion efficiency in photo-electrochemical cells. The goal is to create an efficient, stable photo-electrochemical cell capable of converting sunlight into hydrogen and other renewable fuels at elevated temperatures of 500°C to 700°C. Investigators: William Chueh and Nick Melosh, Materials Science and Engineering.

Electrochemical conversion of carbon gases to sustainable fuels and chemicals. Researchers will use computational analysis and experimental techniques to develop new catalysts that convert carbon dioxide and carbon monoxide into renewable fuels and chemicals. Investigators: Thomas Jaramillo, Chemical Engineering; Jens Nørskov, Chemical Engineering and SLAC National Accelerator Laboratory; Anders Nilsson, SLAC.

A team of scientists from the United States, Belgium and Scotland also received support for research that could lead to the large-scale conversion of cellulosic plants to biofuels:

Optimizing yield and composition in lignin‐modified plants. The inability to process lignin, a cement-like component of plant cell walls, has been a major hurdle in the production of biofuels from switchgrass and other cellulosic plants. In a previous GCEP study, the research team genetically engineered plants with reduced lignin that were smaller than normal. This project seeks to develop larger lignin-modified plants that can be cultivated for biofuels at scale. Investigators: Clint Chapple, Purdue University; Wout Boerjan, VIB and University of Ghent (Belgium); John Ralph, University of Wisconsin-Madison; Xu Li, North Carolina State University; Claire Halpin and Gordon Simpson, University of Dundee (Scotland).

GCEP is an industry partnership that supports innovative research on energy technologies that address the challenge of global climate change by reducing greenhouse gas emissions. Based at Stanford, the project includes five corporate sponsors – ExxonMobil, GE, Schlumberger, DuPont and Bank of America.

###

For more information visit http://gcep.stanford.edu.

This article was written by Mark Shwartz, Precourt Institute for Energy, Stanford University.

New “gold nanocluster” Technology Revolutionizes Solar Power


QDOT images 6Scientists at Western University have discovered that a small molecule created with just 144 atoms of gold can increase solar cell performance by more than 10 per cent.

 

 

 

These findings, published recently by the high-impact journal Nanoscale, represent a game-changing innovation that holds the potential to take solar power mainstream and dramatically decrease the world’s dependence on traditional, resource-based sources of energy, says Giovanni Fanchini from Western’s Faculty of Science.

Fanchini, the Canada Research Chair in Carbon-based Nanomaterials and Nano-optoelectronics, says the new technology could easily be fast-tracked and integrated into prototypes of solar panels in one to two years and solar-powered phones in as little as five years.

“Every time you recharge your cell phone, you have to plug it in,” says Fanchini, an assistant professor in Western’s Department of Physics and Astronomy. “What if you could charge mobile devices like phones, tablets or laptops on the go? Not only would it be convenient, but the potential energy savings would be significant.”

The Western researchers have already started working with manufacturers of solar components to integrate their findings into existing and are excited about the potential.

“The Canadian business industry already has tremendous know-how in solar manufacturing,” says Fanchini. “Our invention is modular, an add-on to the existing production process, so we anticipate a working prototype very quickly.”

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Making nanoplasmonic enhancements, Fanchini and his team use “gold nanoclusters” as building blocks to create a flexible network of antennae on more traditional to attract an increase of light. While nanotechnology is the science of creating functional systems at the molecular level, nanoplasmonics investigates the interaction of light with and within these systems.

“Picture an extremely delicate fishnet of gold,” explains Fanchini explains, noting that the antennae are so miniscule they are unseen even with a conventional optical microscope. “The fishnet catches the light emitted by the sun and draws it into the active region of the solar cell.”

1-watchingnano

According to Fanchini, the spectrum of light reflected by gold is centered on the yellow colour and matches the light spectrum of the sun making it superior for such antennae as it greatly amplifies the amount of sunlight going directly into the device.

“Gold is very robust, resilient to oxidization and not easily damaged, making it the perfect material for long-term use,” says Fanchini. “And gold can also be recycled.”

It has been known for some time that larger gold nanoparticles enhance solar cell performance, but the Western team is getting results with “a ridiculously small amount” – approximately 10,000 times less than previous studies, which is 10,000 times less expensive too.

Explore further: Using solar energy to turn raw materials into ingredients for everyday life

Provided by University of Western Ontario

Novel Solar Cell Production Using X-Ray Imaging


X Ray Solar id37265The sharp X-ray vision of DESY’s research light source PETRA III paves the way for a new technique to produce cheap, flexible and versatile double solar cells. The method developed by scientists from the Technical University of Denmark (DTU) in Roskilde can reliably produce efficient tandem plastic solar cells of many metres in length, as a team around senior researcher Jens W. Andreasen reports in the journal Advanced Energy Materials (“Enabling Flexible Polymer Tandem Solar Cells by 3D Ptychographic Imaging”).

 

The scientists used a production process, where the different layers of a polymer (plastic) solar cell are coated from various solutions onto a flexible substrate. This way, the solar cell can be produced fast and cheap in a roll-to-roll process and in almost any desired length – up to several kilometers long single solar cell modules have already been manufactured. However, the energy harvesting efficiency of this type of solar cell is not very high. To increase the efficiency, a DTU team around Frederik C. Krebs stacked two such solar cells onto each other. Each of these absorbs a different part of the solar spectrum, so that the resulting tandem polymer solar cell converts more of the incoming sunlight into electric energy. But the multilayer coating presents several new challenges, as Andreasen explained: “Lab studies have shown that already coated layers may be dissolved by the solvent from the following layer, causing complete failure of the solar cell.”

 

X Ray Solar id37265

Ptychographic phase contrast projection of the polymer tandem solar cell stack (two by four microns in size), showing the silver electrode (lower green band) with a polymer layer on top, the upper electrode (upper green band, with red) and the zinc oxide layer (narrow dark blue band) between the two solar cells. The green triangel on top of the sample is the cut-off of a wolfram pin used to manipulate the sample under a scanning electron microscope. (Image: Jens Wenzel Andreasen/DTU)

To prevent redissolution of the first solar cell, the scientists added a carefully composed protective intermediate coating between the two solar cells. The protective coating contains a layer made of zinc oxide (ZnO) that is just 40 nanometres thick – about a thousand times thinner than a human hair. To check shape and function of the protective coating and the other layers of the tandem solar cell, the scientists used the exceptionally sharp X-ray vision of DESY’s research light source PETRA III that can reveal finest details. “The solar cell structure is very delicate, consisting of twelve individual layers altogether.

Imaging the complete structure is challenging,” explained co-author Juliane Reinhardt from DESY’s experimental station P06 where the investigations were made. “And the sample was just two by four microns in size.” Still, with the brilliant X-ray beam from PETRA III, the researchers could peer into the layer structure in fine detail, using a technique called 3D ptychography. This method reconstructs the three-dimensional shape and chemistry of a sample from the way it diffracts the incoming X-rays. For a full 3D reconstruction a great number of overlapping X-ray diffraction images have to be recorded from all sides and angles. The advantage of ptychography is that it yields a higher resolution than would be possible with conventional X-ray imaging alone. And in contrast to electron microscopy, X-ray ptychography can also look deep inside the sample.

“With 3D ptychography, we were able to image the complete roll-to-roll coated tandem solar cell, showing, among other things, the integrity of the 40 nanometres thin zinc oxide layer in the protective coating that successfully preserved underlying layers from solution damage,” said DESY scientist Gerald Falkenberg, head of the experimental station P06. “These are the 3D ptychography measurements with the highest spatial resolution we have achieved so far. The results show that with the correct formulation of the intermediate layer, the underlying solar cell is protected from redissolution.”

The investigation paves the way to a possible industrial application of the new technique. “In a complex multilayer device like a polymer tandem solar cell, the device may fail in multiple ways,” Andreasen pointed out.

“What we were able to see with 3D ptychography was that the preparation of the substrate electrode combines the good conductivity of a coarsely structured silver electrode with the good film forming ability of a conducting polymer that infiltrates the silver electrode and forms a smooth surface for the coating of the subsequent layers.” This is what allows the coating of very thin layers, at very high speeds, still forming contiguous layers, without pinholes.

Looking into the complete structure can also provide valuable information for a possible optimization of the device and the production process. “In principle we make the devices without knowing what the internal structure looks like in detail. But knowing the structure tells us which parameters we can modify, and which factors are important for the device architecture, for example the special type of substrate electrode, and the formulation of the intermediate layer,” Andreasen explained.

“We were now able to verify that we can coat contiguous, homogeneous layers, roll-to-roll from solution, at speeds up to several meters per minute. We have shown that roll-to-roll processing of tandem solar cells is possible, with all of the layers roll-coated from solution, and that it is only possible using a specific formulation of the intermediate layer between the two sub-cells.”

The resulting polymer tandem solar cell converts 2.67 per cent of the incoming sunlight into electric energy, which is way below the efficiency of conventional solar cells. “The efficiency is low, compared to conventional solar cells, by a factor of 7 to 8, but one should consider that the production cost of this type of solar cell is several orders of magnitude lower than for conventional solar cells. This is the particular advantage of polymer solar cells,” explained Andreasen. “Furthermore, this is the first example of a roll-to-roll coated tandem solar cell where the efficiency of the tandem device actually exceeds that of the individual sub-cell devices by themselves.”
Source: DESY

 

 

 

 

 

 

Genesis Nanotech ‘News and Updates’ – September 9, 2014


Nano Sensor for Cancer 50006

Genesis Nanotech ‘News and Updates’ – September 9, 2014

Follow This Link: https://paper.li/GenesisNanoTech/1354215819#

Or by Individual Articles:

Transfer Printing Methods for Flexible Thin Film Solar Cells: Basic Concepts and Working Principles – ACS Nano (ACS Publications)

Nanotechnology to slash NOx and “cancerous” emissions

Tumor-Homing, Size-Tunable Clustered Nanoparticles for Anticancer Therapeutics – ACS Nano (ACS Publications)

New Detector Capable of Capturing Terahertz Waves at Room Temperature

Quotable Coach: Plug In And Participate – The Multiplier Mindset: Insights & Tips for Entrepreneurs

Genesis Nanotechnology – “Great Things from Small Things!”

10 Emerging Technologies That Will Change/ Have Changed (?) Your World


CNT multiprv1_jpg71ec6d8c-a1e2-4de6-acb6-f1f1b0a66d46LargerNote to Readers: It is interesting (To Us at GNT anyway) that the BOLD predictions for technology, should always be IOHO “re-visited”. What follows is the “Top 10 List” from 2004. 10 Years … How have the technology “fortune-tellers” done?!

 

 

10 Emerging Technologies That Will Change Your World

Technology Review unveils its annual selection of hot new technologies about to affect our lives in revolutionary ways-and profiles the innovators behind them.

Full Article Link Here: http://www2.technologyreview.com/featured-story/402435/10-emerging-technologies-that-will-change-your/

Technology Review: February 2004

With new technologies constantly being invented in universities and companies across the globe, guessing which ones will transform computing, medicine, communication, and our energy infrastructure is always a challenge. Nonetheless, Technology Review’s editors are willing to bet that the 10 emerging technologies highlighted in this special package will affect our lives and work in revolutionary ways-whether next year or next decade. For each, we’ve identified a researcher whose ideas and efforts both epitomize and reinvent his or her field. The following snapshots of the innovators and their work provide a glimpse of the future these evolving technologies may provide.

10 Emerging Technologies That Will Change Your World
Universal Translation
Synthetic Biology
Nanowires
T-Rays
Distributed Storage
RNAi Interference
Power Grid Control
Microfluidic Optical Fibers
Bayesian Machine Learning
Personal Genomics

Excerpt: Nanowires:

(Page 4 of 11)

PEIDONG YANG

Nanowires

Few emerging technologies have offered as much promise as nanotechnology, touted as the means of keeping the decades-long electronics shrinkfest in full sprint and transfiguring disciplines from power production to medical diagnostics. Companies from Samsung Electronics to Wilson Sporting Goods have invested in nanotech, and nearly every major university boasts a nanotechnology initiative. Red hot, even within this R&D frenzy, are the researchers learning to make the nanoscale wires that could be key elements in many working nanodevices.

“This effort is critical for the success of the whole [enterprise of] nanoscale science and technology,” says nanowire pioneer Peidong Yang of the University of California, Berkeley. Yang has made exceptional progress in fine-tuning the properties of nanowires. Compared to other nanostructures, “nanowires will be much more versatile, because we can achieve so many different properties just by varying the composition,” says Charles Lieber, a Harvard University chemist who has also been propelling nanowire development.

The World Of Tomorrow: Nanotechnology: Interview with PhD and Attorney D.M. Vernon


Bricks and Mortar chemistsdemoThe Editor interviews Deborah M. VernonPhD, Partner in McCarter & English, LLP’s Boston office.

 

 

 

Why It Matters –

” … I would say the two most interesting areas in the last year or two have been in 3-D printing and nanotechnology. 3-D printing is an additive technology in which one is able to make a three-dimensional product, such as a screw, by adding material rather than using a traditional reduction process, like a CNC (milling) process or a grinding-away process.

The other interesting area has been nanotechnology. Nanotechnology is the science of materials and structures that have a dimension in the nanometer range (1-1,000 nm) – that is, on the atomic or molecular scale. A fascinating aspect of nanomaterials is that they can have vastly different material properties (e.g., chemical, electrical, mechanical properties) than their larger-scale counterparts. As a result, these materials can be used in applications where their larger-scale counterparts have traditionally not been utilized.”

nanotech

Editor: Deborah, please tell us about the specific practice areas of intellectual property in which you participate.

 

 

Vernon: My practice has been directed to helping clients assess, build, maintain and enforce their intellectual property, especially in the technology areas of material science, analytical chemistry and mechanical engineering. Prior to entering the practice of law, I studied mechanical engineering as an undergraduate and I obtained a PhD in material science engineering, where I focused on creating composite materials with improved mechanical properties.

Editor: Please describe some of the new areas of biological and chemical research into which your practice takes you, such as nanotechnology, three-dimensional printing technology, and other areas.

Vernon: I would say the two most interesting areas in the last year or two have been in 3-D printing and nanotechnology. 3-D printing is an additive technology in which one is able to make a three-dimensional product, such as a screw, by adding material rather than using a traditional reduction process, like a CNC (milling) process or a grinding-away process. The other interesting area has been nanotechnology. Nanotechnology is the science of materials and structures that have a dimension in the nanometer range (1-1,000 nm) – that is, on the atomic or molecular scale.

A fascinating aspect of nanomaterials is that they can have vastly different material properties (e.g., chemical, electrical, mechanical properties) than their larger-scale counterparts. As a result, these materials can be used in applications where their larger-scale counterparts have traditionally not been utilized.

Organ on a chip organx250

I was fortunate to work in the nanotech field in graduate school. During this time, I investigated and developed methods for forming ceramic composites, which maintain a nanoscale grain size even after sintering. Sintering is the process used to form fully dense ceramic materials. The problem with sintering is that it adds energy to a system, resulting in grain growth of the ceramic materials. In order to maintain the advantageous properties of the nanosized grains, I worked on methods that pinned the ceramic grain boundaries to reduce growth during sintering.

The methods I developed not only involved handling of nanosized ceramic particles, but also the deposition of nanofilms into a porous ceramic material to create nanocomposites. I have been able to apply this experience in my IP practice to assist clients in obtaining and assessing IP in the areas of nanolaminates and coatings, nanosized particles and nanostructures, such as carbon nanotubes, nano fluidic devices, which are very small devices which transport fluids, and 3D structures formed from nanomaterials, such as woven nanofibers.

Editor: I understand that some of the components of the new Boeing 787 are examples of nanotechnology.

Vernon: The design objective behind the 787 is that lighter, better-performing materials will reduce the weight of the aircraft, resulting in longer possible flight times and decreased operating costs. Boeing reports that approximately 50 percent of the materials in the 787 are composite materials, and that nanotechnology will play an important role in achieving and exceeding the design objective. (See, http://www.nasc.com/nanometa/Plenary%20Talk%20Chong.pdf).

While it is believed that nanocomposite materials are used in the fuselage of the 787, Boeing is investigating applying nanotechnology to reduce costs and increase performance not only in fuselage and aircraft structures, but also within energy, sensor and system controls of the aircraft.

Editor: What products have incorporated nanotechnology? What products are anticipated to incorporate its processes in the future?

Vernon: The products that people are the most familiar with are cosmetic products, such as hair products for thinning hair that deliver nutrients deep into the scalp, and sunscreen, which includes nanosized titanium dioxide and zinc oxide to eliminate the white, pasty look of sunscreens. Sports products, such as fishing rods and tennis rackets, have incorporated a composite of carbon fiber and silica nanoparticles to add strength. Nano products are used in paints and coatings to prevent algae and corrosion on the hulls of boats and to help reduce mold and kill bacteria. We’re seeing nanotechnology used in filters to separate chemicals and in water filtration.

The textile industry has also started to use nano coatings to repel water and make fabrics flame resistant. The medical imaging industry is starting to use nanoparticles to tag certain areas of the body, allowing for enhanced MRI imaging. Developing areas include drug delivery, disease detection and therapeutics for oncology. Obviously, those are definitely in the future, but it is the direction of scientific thinking.

Editor: What liabilities can product manufacturers incur who are incorporating nanotechnology into their products? What kinds of health and safety risks are incurred in their manufacture or consumption?Nano Body II 43a262816377a448922f9811e069be13

Vernon: There are three different areas that we should think about: the manufacturing process, consumer use and environmental issues. In manufacturing there are potential safety issues with respect to the incorporation or delivery of nanomaterials. For example, inhalation of nanoparticles can cause serious respiratory issues, and contact of some nanoparticles with the skin or eyes may result in irritation. In terms of consumer use, nanomaterials may have different material properties from their larger counterparts.

As a result, we are not quite sure how these materials will affect the human body insofar as they might have a higher toxicity level than in their larger counterparts. With respect to an environmental impact, waste or recycled products may lead to the release of nanoparticles into bodies of water or impact wildlife. The National Institute for Occupational Safety and Health has established the Nanotechnology Research Center to develop a strategic direction with respect to occupational safety and nanotechnology. Guidance and publications can be found at http://www.cdc.gov/niosh/topics/nanotech.

Editor: The European Union requires the labeling of foods containing nanomaterials. What has been the position of the Food & Drug Administration and the EPA in the United States about food labeling?

Vernon: So far the FDA has taken the position that just because nanomaterials are smaller, they are not materially different from their larger counterparts, and therefore there have been no labeling requirements on food products. The FDA believes that their current standards for safety assessment are robust and flexible enough to handle a variety of different materials. That being said, the FDA has issued some guidelines for the food and cosmetic industries, but there has not been any requirement for food labeling as of now. The EPA has a nanotechnology division, which is also studying nanomaterials and their impact, but I haven’t seen anything that specifically requires a special registration process for nanomaterials.

Editor: What new regulations regarding nanotech products are expected? Should governmental regulations be adopted to prevent nanoparticles in foods and cosmetics from causing toxicity?

Vernon: The FDA has not telegraphed that any new regulations will be put into place. The agency is currently in the data collection stage to make sure that these materials are being safely delivered to people using current FDA standards – that materials are safe for human consumption or contact with humans. We won’t really understand whether or not regulations will be coming into place until we see data coming out that indicates that there are issues that are directly associated with nanomaterials. Rather than expecting regulations, I would suggest that we examine the data regarding nano products to optimize safe handling and use procedures.

Editor: Have there ever been any cases involving toxicity resulting from nano products?

Vernon: There are current investigations about the toxicity of carbon nano tubes, but the research is in its infancy. There is no evidence to show any potential harm from this technology. Unlike asbestos or silica exposure, the science is not there yet to demonstrate any toxicity link. The general understanding is that it may take decades for any potential harm to manifest. I believe my colleague, Patrick J. Comerford, head of McCarter’s product liability team in Boston, summarizes the situation well by noting that “if any supportable science was available, plaintiff’s bar would have already made this a high-profile target.”

Editor: While some biotech cases have failed the test of patentability before the courts, such as the case of Mayo v. Prometheus, what standard has been set forth for a biotech process to pass the test for patentability?

Vernon: There is no specified bright-line test for determining if a biotech process is patentable. But what the U.S. Patent and Trademark Office has done is to issue some new examination guidelines with respect to the Mayo decision that help examiners figure out whether a biotech process is patent eligible. Specifically, the guidelines look to see if the biotech process (i.e., a process incorporating a law of nature) also includes at least one additional element or step. That additional element needs to be significant and not just a mental or correlation step. If a biotech process patent claim includes this significant additional step, there still needs to be a determination if the process is novel and non-obvious over the prior art. So while this might not be a bright-line test to help us figure out whether a biotech process is patentable, it at least gives us some direction about what the examiners are looking for in the patent claims.

Editor: What effect do you think the new America Invents Act will have in encouraging biotech companies to file early in the first stages of product development? Might that not run the risk that the courts could deny patentability as in the Ariad case where functional results of a process were described rather than the specific invention?

Vernon: The AIA goes into effect next month. What companies, especially biotech companies, need to do is file early. Companies need to submit applications supported by their research to include both a written description and enablement of the invention. Companies will need to be more focused on making sure that they are not only inventing in a timely manner but are also involving their patent counsel in planned and well-thought-out experiments to make sure that the supporting information is available in a timely fashion for patenting.

Editor: Have there been any recent cases relating to biotechnology or nanotechnology that our readers should be informed about?

Vernon: The Supreme Court will hear oral arguments in April in the Myriad case. This case involves the BRCA gene, the breast cancer gene – and the issue is whether isolating a portion of a gene is patentable. While I am not a biotechnologist, I think this case will also impact nanotechnology as a whole. Applying for a patent on a portion of a gene is not too far distant from applying for a patent on a nanoparticle of a material that already exists but which has different properties from the original, larger-counterpart material. Would this nanosize material be patentable? This will be an important case to see what guidance the Supreme Court delivers this coming term.

Editor: Is there anything else you’d like to add?

Vernon: I think the next couple of years for nanotech will be very interesting. As I mentioned, I did my PhD thesis in the nanotechnology area a few years ago. My studies, like those of many other students, were funded in part with government grants. There is a great deal of government money being poured into nanotechnology. In the next ten years we will start seeing more and more of this research being commercialized and adopted into our lives. To keep current of developments, readers can visit www.nano.gov.

The Metropolitan Corporate Counsel
The Leading Resource For Corporate Counsel

As a leading publication in the corporate counsel community, MCC offers unique editorial content covering legal, regulatory, legislative and business developments, featuring original articles and interviews from experts at prestigious law firms, bar associations, accounting firms and legal service providers, as well as educators, business executives and high-level state, national and international officials.

 

Breaking the Space Charge Limit in Organic Solar Cells: Why It Matters


Hong Kong Organic SC srep06236-f1

Why It Matters – “Most importantly, the plasmonic-electrical concept will open up a new way to manipulate both optical and electrical properties of semiconductor devices simultaneously.”

” … Understanding the SCL (space charge limit) effect is important to manipulate transport, recombination, and extraction of photocarriers, which will significantly affect the power conversion efficiency (PCE) of OSCs. (Organic Solar Cells)”

As a fundamental electrostatic limit, space charge limit (SCL) for photocurrent is a universal phenomenon and of paramount importance for organic semiconductors with unbalanced photocarriers mobility and high exciton generation. Here we proposed a new plasmonic-electrical concept to manipulate electrical properties of organic devices including photocarriers recombination, transport and collection.

 

As a proof-of-concept, organic solar cells (OSCs) comprising metallic planar and grating electrodes are systematically investigated with normal and inverted device structures. Interestingly, although strong plasmonic resonances induce abnormally dense photocarriers around a grating anode, the grating-inverted OSC is exempt from space charge accumulation (limit) and degradation of electrical properties in contrast to the planar-inverted and planar-normal ones.

The particular reason is that plasmonically induced photocarriers redistribution shortens the transport path of low-mobility holes, which are collected by the grating anode. The work demonstrated and explained the SCL breaking with the plasmonic-electrical effect. Most importantly, the plasmonic-electrical concept will open up a new way to manipulate both optical and electrical properties of semiconductor devices simultaneously.

This work is supported by the General Research Fund (grants: HKU711813 and HKU711612E), the National Natural Science Foundation of China (NSFC)/Research Grants Council (RGC) grant (N_HKU709/12) and Ministry of Education (MOE)/Research Grants Council (RGC) (M-HKU703/12) from RGC of Hong Kong Special Administrative Region, China. This project is also supported in part by Collaborated Research Fund (CUHK1/CRF/12G) of RGC, NSFC grant (No. 61201122), and UGC of Hong Kong (No. AoE/P-04/08).

Abstract ** The complete referenced article is available here online at:

http://www.nature.com/srep/2014/140829/srep06236/full/srep06236.html

The space charge limit (SCL) effect is a universal phenomenon in semiconductor devices involving light emitting diodes, solar cells, and photodetectors1, 2, 3, 4, 5, 6, 7, 8, 9. It also sets a fundamental electrostatic limit in electrical properties of organic semiconductor devices with unbalanced photocarriers (electrons and holes) mobility and high exciton generation efficiency10, 11, 12, 13, 14. With the interesting features of low cost, low-temperature fabrication, semi-transparency, and mechanical flexibility, organic solar cell (OSC) is currently one of emerging optoelectronic devices and shows a bright outlook for green energy industry12, 13, 15, 16, 17, 18. Understanding the SCL effect is important to manipulate transport, recombination, and extraction of photocarriers, which will significantly affect the power conversion efficiency (PCE) of OSCs.

 

Hong Kong SC 2 srep06236-f1

 

Typically, the occurrence of SCL4 satisfies the following conditions: (1) unbalanced hole and electron mobility; (2) thick active layer; (3) high light intensity or dense photocarriers (electrons and holes) generation; and (4) moderate reverse bias. Compared to electron mobility, a low mobility of holes typically occurs in organic semiconductor devices depending on fabrication procedures19, 20, 21, 22 e.g. thermal annealing, solvent annealing, etc; and even occurs in the OSCs with robust active materials such as the polymer blend of poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM). To investigate SCL characteristics, the inverted OSC with a planar multilayered structure is taken as a representative example. In the planar-inverted OSCs, photocarriers will be generated at the region close to the transparent cathode, such as indium tin oxide (ITO), where incident light will first penetrate. The photogenerated holes with a low mobility will have to transport through the whole active layer, and finally reach the anode (see Figure 1(a)). SCL will occur if the length of active layer is longer than the mean drift length of holes, which is very short because of the low mobility. Meanwhile, holes pile up inside the device to a greater degree than electrons. In other words, positive space charges are accumulated due to the unbalanced photocarriers mobility and a long transport path of holes. As a result, the short-circuit current and fill factor of OSCs will drop significantly due to both the bulk recombination and space charge formation4, 7, 9, 23, 24. In this work, we will demonstrate the SCL breaking in the OSCs incorporating metallic (Ag or Au) nanostructures, which offers a novel route to eliminate the SCL effect in semiconductor devices.

(For the complete article see this link)

http://www.nature.com/srep/2014/140829/srep06236/full/srep06236.html

“Genesis Nanotechnology – Great Things from Small Things”

New Nanoparticle (Quantum Dots) Brings Cheaper, Lighter Solar cells


U T Q Dot Solar newclassofnaThink those flat, glassy solar panels on your neighbor’s roof are the pinnacle of solar technology? Think again!

 

 

Researchers in the University of Toronto’s Edward S. Rogers Sr. Department of Electrical & Computer Engineering have designed and tested a new class of solar-sensitive nanoparticle that outshines the current state of the art employing this new class of technology.

This new form of solid, stable light-sensitive nanoparticles, called colloidal , could lead to cheaper and more flexible , as well as better gas sensors, infrared lasers, infrared light emitting diodes and more. The work, led by post-doctoral researcher Zhijun Ning and Professor Ted Sargent, was published this week in Nature Materials.

U T Q Dot Solar newclassofna

Diagram of quantum dot. Credit: University of Toronto

 

Collecting sunlight using these tiny colloidal quantum dots depends on two types of semiconductors: n-type, which are rich in electrons; and p-type, which are poor in electrons. The problem? When exposed to the air, n-type materials bind to oxygen atoms, give up their electrons, and turn into p-type. Ning and colleagues modelled and demonstrated a new colloidal quantum dot n-type material that does not bind oxygen when exposed to air.

Maintaining stable n- 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.

Dr. Zhijun Ning in the lab, holding a film coated with colloidal quantum dots. Credit: Roberta Baker

“This is a material innovation, that’s the first part, and with this new material we can build new device structures,” said Ning. “Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stability—no one has shown that before.”

Ning’s new hybrid n- and p-type material achieved solar power conversion efficiency up to eight per cent—among the best results reported to date.

This is a photo of co-authors Zhijun Ning (left) and Oleksandr Voznyy (right) examining a film coated with colloidal quantum dots. Credit: Roberta Baker

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 and painted or printed onto thin, flexible surfaces, such as roofing shingles, dramatically lowering the cost and accessibility of solar power for millions of people.

“The field of colloidal quantum dot photovoltaics requires continued improvement in absolute performance, or power conversion efficiency,” said Sargent. “The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels.”

Explore further: New breed of solar cells: Quantum-dot photovoltaics set new record for efficiency in such devices