High-Efficiency Quantum Dot Solar Cells Developed


QDOTS imagesCAKXSY1K 8Oct. 26, 2012 — Research shows newly developed solar powered cells may soon outperform conventional photovoltaic technology. Scientists from the National Renewable Energy Laboratory (NREL) have demonstrated the first solar cell with external quantum efficiency (EQE) exceeding 100 percent for photons with energies in the solar range. (The EQE is the percentage of photons that get converted into electrons within the device.)


The researchers will present their findings at the AVS 59th International Symposium and Exhibition, held Oct. 28 — Nov. 2, in Tampa, Fla.

While traditional semiconductors only produce one electron from each photon, nanometer-sized crystalline materials such as quantum dots avoid this restriction and are being developed as promising photovoltaic materials. An increase in the efficiency comes from quantum dots harvesting energy that would otherwise be lost as heat in conventional semiconductors. The amount of heat loss is reduced and the resulting energy is funneled into creating more electrical current.

By harnessing the power of a process called multiple exciton generation (MEG), the researchers were able to show that on average, each blue photon absorbed can generate up to 30 percent more current than conventional technology allows. MEG works by efficiently splitting and using a greater portion of the energy in the higher-energy photons. The researchers demonstrated an EQE value of 114 percent for 3.5 eV photons, proving the feasibility of this concept in a working device.

Joseph Luther, a senior scientist at NREL, believes MEG technology is the right direction. “Since current solar cell technology is still too expensive to completely compete with non-renewable energy sources, this technology employing MEG demonstrates that the way in which scientists and engineers think about converting solar photons to electricity is constantly changing,” Luther said. “There may be a chance to dramatically increase the efficiency of a module, which could result in solar panels that are much cheaper than non-renewable energy sources.”

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Nanotech Antennas Could Help Solar Cell Efficiency Soar


QDOTS imagesCAKXSY1K 8A new technology for the fabrication of nanotech antennas promises to lift the efficiency level of silicon solar cells from its current 10 per cent to a staggering and unprecedented 70 per cent.

Scientists have long touted the theoretical promise of nano-sized antennas called “retennas”, thus named for their ability to simultaneously absorb solar energy and rectify it from alternating current to direct current.

Calculations indicate that a solar cell comprised of retennas should be capable of reaping over 70 per cent of  the sun’s electromagnetic radiation for conversion into electricity, a remarkable amount given that the most advanced silicon panels available at present are capable of harvesting only 20 per cent of available solar radiation.

Though the technology has long shown immense promise on the drawing board, it has proven extremely difficult to achieve in reality, however, due to the challenges involved in the nanotech fabrication of the antennas.

The distance between the core pair of electrodes in the rectennas must be between one and two nanometers apart,  a distance equal to about a millionth of a millimetre.

This tiny gap holds the key to both the rectenna’s heightened efficiency and the increased challenge of fabrication. The nano-sized gap permits the maximum transfer of electricity between the electrode pairs by creating an ultra-fast tunnel junction, which gives energized electrons the just the right amount of time to leap onto the other electrode before the electrical current reverses.

The rectenna further requires that one of two interior electrodes ends in a pointed tip in order to prevent electrons from reversing direction, thus trapping their movement and “rectifying” it in a unidirectional current. This pointed tip further heightens the difficulty of fabricating the tiny devices.

nanosized optical rectifying antenna

Illustration of a working nanosized optical rectifying antenna or rectenna. Credit: Brian Willis

A breakthrough fabrication process promises to overcome these difficulties and bridge the gap between the theory and practice, however. The technique, called Selective Area Atomic Layer Deposition (ALD) should enable scientists to fashion rectenna devices to the precise shape and dimensions required for successful operation.

ALD is able to overcome fabrication difficulties by gradually coating the tip of the electrode head with layers of individual copper atoms, until the precise gap of 1.5 nanometers is achieved.

Prior to the development of ALD, scientists struggled to fashion the tiny gap that the rectenna requires using even the most precise and sophisticated of nanotech devices.  Electron guns could only to fashion a gap 10 times greater than the required distance.

The new breakthrough technology was developed by Brian Willis, an associate professor of chemicals, materials and biomolecular engineering at the University of Connecticut’s Chemical Engineering Program. Willis patented the ALD process in 2011 after developing it during a teaching stint at the University of Delaware.

Willis believes the application of retennas to photovoltaic technology could radically change the future of solar energy by making it cost-competitive with fossil fuels.

He has already teamed up with a group of scientists from Penn State Altoona as well as private Pennsylvania-based company SciTechAssociates Holdings Inc. to engage in the research and manufacture of rectennas and received a $650,000 three-year grant from the National Science Foundation to further his team’s efforts.

Giving Transplanted Cells a Nanotech Checkup


QDOTS imagesCAKXSY1K 8Feb. 5, 2013 — Researchers at Johns Hopkins have devised a way to detect whether cells previously transplanted into a living animal are alive or dead, an innovation they say is likely to speed the development of cell replacement therapies for conditions such as liver failure and type 1 diabetes. As reported in the March issue of Nature Materials, the study used nanoscale pH sensors and magnetic resonance imaging (MRI) machines to tell if liver cells injected into mice survived over time.


 “This technology has the potential to turn the human body into less of a black box and tell us if transplanted cells are still alive,” says Mike McMahon, Ph.D., an associate professor of radiology at the Johns Hopkins University School of Medicine who oversaw the study. “That information will be invaluable in fine-tuning therapies.”

Regenerative medicine advances depend on reliable means of replacing damaged or missing cells, such as injecting pancreatic cells in people with diabetes whose own cells don’t make enough insulin. To protect the transplanted cells from the immune system, while allowing the free flow of nutrients and insulin between the cells and the body, they can be encased in squishy hydrogel membranes before transplantation. But, explains McMahon, “once you put the cells in, you really have no idea how long they survive.” Such transplanted cells eventually stop working in most patients, who must resume taking insulin. At that point, physicians can only assume that cells have died, but they don’t know when or why, says McMahon.

With that problem in mind, McMahon’s group, which specializes in methods of detecting chemical changes, collaborated with the research group headed by Jeff Bulte, Ph.D., the director of cellular imaging at Hopkins’ Institute for Cell Engineering. Bulte’s group devises ways of tracking implanted cells through the body using MRI. Led by research fellow Kannie Chan, Ph.D., the team devised an extremely tiny, or nanoscale, sensor filled with L-arginine, a nutritional supplement that responds chemically to small changes in acidity (pH) caused by the death of nearby cells. Changes in the acidity would in turn set off changes in sensor molecules embedded in the thin layer of fat that makes up the outside of the nanoparticle, giving off a signal that could be detected by MRI.

To test how these nanosensors would work in a living body, the team loaded them into hydrogel spheres along with liver cells — a potential therapy for patients with liver failure — and another sensor that gives off bioluminescent light only while the cells are alive. The spheres were injected just under the skin of mice. As confirmed by the light signal, the MRI accurately detected where the cells were in the body and what proportion were still alive. (Such light indicators cannot be used to track cells in humans because our bodies are too large for visible signals to get through, but these indicators allowed the team to check whether the MRI nanosensors were working properly in the mice.)

“It was exciting to see that this works so well in a living body,” Chan says. The team hopes that because the components of the system — hydrogel membrane, fat molecules, and L-arginine — are safe for humans, adapting their discovery for clinical use will prove relatively straightforward. “This should take a lot of the guesswork out of cell transplantation by letting doctors see whether the cells survive, and if not, when they die,” Chan says. “That way they may be able to figure out what’s killing the cells, and how to prevent it.”

Potential applications of the sensors are not limited to cells inside hydrogel capsules, Bulte notes. “These nanoparticles would work outside capsules, and they could be paired with many different kinds of cells. For example, they may be used to see whether tumor cells are dying in response to chemotherapy,” he says.

Other authors on the paper were Guanshu Liu, Xiaolei Song, Heechul Kim, Tao Yu, Dian R. Arifin, Assaf A. Gilad, Justin Hanes, Piotr Walczak and Peter C. M. van Zijl, all of the Johns Hopkins University School of Medicine.

The study was funded by the National Institute of Biomedical Imaging and Bioengineering (grant numbers R01 EB012590, EB015031, EB015032 and EB007825).

China, India Emerge as Most Promising High-Growth Markets for Solar


QDOTS imagesCAKXSY1K 8Japan, U.K., France, and South Korea also offer attractive landscape and large addressable markets, according to Lux Research‘s analysis of policy and market drivers

 

BOSTON, Feb 12, 2013 (BUSINESS WIRE) — Global policy changes and the crystalline silicon module price crash have brought the solar industry to a pivotal point from which it must transform and thrive in a cost-conscious environment, targeting high-growth markets such as China and India, says Lux Research.

“While some historically strong demand markets will continue to pay dividends, the real winners going forward will need to make a few well-informed bets,” said Matt Feinstein, Lux Research Analyst and the lead author of the report titled, “Past is Prologue: Market Selection Strategy in a New Solar Policy Environment.”

“Successful players will anchor business in key developed regions like the U.S., Europe, Japan, and China, and place informed bets in markets like South/Central America, the Middle East, and Africa, through new offices or partnerships,” he added.

Lux Research analyzed the risk vs. reward, based on policy and market factors, for both distributed and utility-scale solar in countries around the world. Among their findings:

— Europe shines for distributed generation. Established markets remain fruitful for distributed generation despite downturns in demand and reduced feed-in tariffs. Markets such as Germany and Italy have demonstrated a strong preference for rooftop systems and have strong existing channels to market.

— Utility-scale generation soars in emerging markets. High-growth markets come with high risks as well, but emerging economies of India, China, South Africa, and Saudi Arabia are set to become solar powers. Competition is booming in the last three in particular, and each will exceed installation targets.

— Fortune favors the bold. In solar, firms that take calculated risks and expand quickly into foreign markets will boost success, as First Solar and many Chinese module manufacturers have shown. As the Chinese industry consolidates, opportunities exist for other global players.

The report, titled “Past is Prologue: Market Selection Strategy in a New Solar Policy Environment,” is part of the Lux Research Solar Systems Intelligence service.

About Lux Research

Lux Research provides strategic advice and ongoing intelligence for emerging technologies. Leaders in business, finance and government rely on us to help them make informed strategic decisions. Through our unique research approach focused on primary research and our extensive global network, we deliver insight, connections and competitive advantage to our clients. Visit http://www.luxresearchinc.com for more information.

http://cts.businesswire.com/ct/CT?id=bwnews&sty=20130212005101r1&sid=cmtx4&distro=nx

SOURCE: Lux Research

Spherical nucleic acids are perfect for biomedical applications


QDOTS imagesCAKXSY1K 8(Nanowerk News) Northwestern University‘s Chad A.  Mirkin, a world-renowned leader in nanotechnology research and its application,  has invented and developed a powerful material that could revolutionize  biomedicine: spherical nucleic acids (SNAs).

“We now can go after a whole new set of diseases,” Mirkin said.  “Thanks to the Human Genome Project and all of the genomics research over the  last two decades, we have an enormous number of known targets. And we can use  the same tool for each, the spherical nucleic acid. We simply change the  sequence to match the target gene. That’s the power of gene regulation  technology.”       

Mirkin will discuss SNAs and their applications in therapeutics  and diagnostics in a talk titled “Nanostructures in Biology and Medicine” at the  American Association for the Advancement of Science (AAAS) annual meeting in  Boston. His presentation is part of the symposium “Convergence of Physical,  Engineering, and Life Sciences: Next Innovation Economy” to be held from 1:30 to  4:30 p.m. Friday, Feb. 15.
Potential applications include using SNAs to carry nucleic  acid-based therapeutics to the brain for the treatment of glioblastoma, the most  aggressive form of brain cancer, as well as other neurological disorders such as  Alzheimer’s and Parkinson’s diseases. Mirkin is aggressively pursuing treatments  for such diseases with Alexander H. Stegh, an assistant professor of neurology  at Northwestern’s Feinberg School of Medicine.
“These structures are really quite spectacular and incredibly  functional,” Mirkin said. “People don’t typically think about DNA in spherical  form, but this novel arrangement of nucleic acids imparts interesting chemical  and physical properties that are very different from conventional nucleic  acids.”
Spherical nucleic acids consist of densely packed, highly  oriented nucleic acids arranged on the surface of a nanoparticle, typically gold  or silver. The tiny non-toxic balls, each roughly 15 nanometers in diameter, can  do things the familiar but more cumbersome double helix can’t do:
  • SNAs  can naturally enter cells and effect gene knockdown, making SNAs a superior tool  for treating genetic diseases using gene regulation technology.
  • SNAs  can easily cross formidable barriers in the human body, including the  blood-brain barrier and the layers that make up skin.
  • SNAs  don’t elicit an immune response, and they resist degradation, resulting in  longer lifetimes in the body.
“The field of medicine needs new constructs and strategies for  treating disease,” Mirkin said. “Many of the ways we treat disease are based on  old methods and materials. Nanotechnology offers the ability to rapidly create  new structures with properties that are very different from conventional forms  of matter.”
Mirkin is the George B. Rathmann Professor of Chemistry in the  Weinberg College of Arts and Sciences and professor of medicine, chemical and  biological engineering, biomedical engineering and materials science and  engineering. He is director of Northwestern’s International Institute for  Nanotechnology (IIN).
Last year, Mirkin and Amy S. Paller, M.D., chair of dermatology  and professor of pediatrics at Feinberg, were the first to demonstrate the use  of commercial moisturizers to deliver gene regulation technology for skin cancer  therapy. The drug, consisting of SNAs, penetrated the skin’s layers and  selectively targeted disease-causing genes while sparing normal genes.
“We now can go after a whole new set of diseases,” Mirkin said.  “Thanks to the Human Genome Project and all of the genomics research over the  last two decades, we have an enormous number of known targets. And we can use  the same tool for each, the spherical nucleic acid. We simply change the  sequence to match the target gene. That’s the power of gene regulation  technology.”
Symposium information:
“Convergence of Physical, Engineering, and Life Sciences: Next  Innovation Economy”; 1:30-4:30 p.m. Friday, February 15; Room 202 (Hynes  Convention Center)
Source: Northwestern University

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Frost & Sullivan Acknowledges that PKC’s Biosensors: New Industry Standard in Pathogen Testing


QDOTS imagesCAKXSY1K 8MOUNTAIN VIEW, Calif., Feb. 13, 2013 /PRNewswire/ — Based on its recent analysis of the global biosensors market, Frost & Sullivan recognizes Pharmaco-Kinesis Corporation (PKC) with the 2013 Global Frost & Sullivan Award for New Product Innovation. The company has set a new standard in the biosensors market with its innovative, highly sensitive biosensor. This unique, multi-pathogen detection device utilizes electrochemical impedance spectroscopy (EIS) to detect pathogens such as E. coli 0157:H7 and the severe acute respiratory syndrome (SARS) virus. It offers higher sensitivity, accuracy, cost-savings. Other key advantages are its greater portability and reusability; and a shorter, less complex testing process than other biosensors in the market. This exhibits PKC’s market expertise and technological excellence.

PKC biosensors’ sample preparation is conducted in a controlled environment, which eliminates the possibility of contamination. Additionally, PKC biosensors require minimal human intervention and provide immediate, real-time pathogen detection. The product has a longer lifespan than similar solutions and can operate efficiently for more than five years with repeated use.

Unlike other pathogen test instruments that utilize test strips or incubators, PKC biosensors use a biosensor container with an electrochemical sensor attached to the base, along with a liquid mixer and a microprocessor that records biosensor readings. This entire device is encased in protective housing, which includes a container holder. This technology lets the pathogen detection status be obtained remotely in real time using radio frequency identification (RFID) readers.

“PKC’s new biosensor offers a number of advantages over the other pathogen test solutions in the market. For example, the lateral flow method requires about eight hours for sample preparation and testing, while PKC’s new technology takes only four hours,” said Frost & Sullivan Research Analyst Dr. Rajender Thusu . “Further, PKC’s technology can detect E. coli 0157:H7, even when it is present in colonies of hundreds, a considerably smaller population than required by other test methods.”

Additionally, PKC’s technology requires a consumable input of only bacteria culture medium, which makes this solution highly cost-effective. Using a vertical orientation of colonies, instead of existing test solutions’ horizontal orientation, significantly accelerates the detection process.

As PKC’s biosensors also offer automated signal generation and high ease of use, it does away with the need to train technicians or use expensive additional equipment. The PKC test instrument requires only an initial investment, instead of the recurring investments needed by other test solutions. Overall, PKC lowers the cost of pathogen testing to almost half of that of lateral-flow technology.

“Although designed for use across a number of application areas, PKC’s biosensors are used primarily in food processing,” noted Dr. Thusu. “They also demonstrate high growth potential in the application areas of patient care monitoring, biodefense, environmental monitoring, and infection control. Another key application area detection of biomarkers related to all cancer types, genetic makers, DAN, RNA and CNS battery of diseases including Alzheimer’s biomarkers, Parkinson and MS.”

PKC’s constant focus on tracking emerging customer needs enables it to introduce industry-first products and solutions designed to offer high customer value and increased return on investment (ROI). PKC is also developing biosensors using nanotechnology, including nanobiosensors, for both in-vivo and in-vitro monitoring of biomarker levels.

PKC is currently working on the first-generation nano-impedance biosensor (NIB) that exhibits the capability to detect high proteins like vascular endorphin growth factor (VEGF). This is likely to enable real-time analysis of tumors in the human body without the need for a blood draw or magnetic resonance imaging (MRI) test.  Every twenty four hours, the body of each human on our planet produces one million cancer cells. Our immune system fights these cancer cells and most often wins the battle every day. Due to weakness of the immune system and reasons that are still unknown, one cancer cell from these one million cells can remain in the body. This rogue cancer cell will then start to grow and can metastasize. The science and medical community unequivocally agrees that – were we capable of detecting these metastatic cancer cells before they grow to about 1 gram in critical mass (about 1 cc in volume) – current treatment modalities could defend against the cancer and save every life. PKC VEGF NIB will give cancer patients to hopefully never experience the pain and suffering of experiencing chemotherapy, tumor resection and death.  The first PKC commercial version of NIB for VEGF will be ready in about six months.

Each year, Frost & Sullivan presents this award to the company that has developed an innovative element in a product by leveraging leading-edge technologies. The award recognizes the value-added features/benefits of the product and the increased ROI it offers customers, which, in turn, increases customer acquisition and overall market penetration potential.

Frost & Sullivan Best Practices Awards recognize companies in a variety of regional and global markets for demonstrating outstanding achievement and superior performance in areas such as leadership, technological innovation, customer service and strategic product development. Industry analysts compare market participants and measure performance through in-depth interviews, analysis and extensive secondary research to identify best practices in the industry.

About Pharmaco-Kinesis Corporation (PKC)

PKC is an advanced medical device company at pre-commercialization stage that aims to optimize the healing of the human body through proprietary local Smart Drug Delivery Systems™ and associated devices to measure biological responses.

This news release contains “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Such statements are based upon the current beliefs and expectations of the management of Pharmaco-Kinesis Corporation and are subject to significant risks and uncertainties. Actual results may differ materially from those set forth in the forward-looking statements. The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.

PR Newswire (http://s.tt/1zK8s)

Quantum Materials Corporation Announces Non-Heavy Metal (Cadmium-Free) Tetrapod Quantum Dots


QDOTS imagesCAKXSY1K 8Quantum Materials Corporation Announces Non-Heavy Metal (Cadmium-Free) Tetrapod Quantum Dots

6:00 AM ET 2/12/13 | PR Newswire

 

quantum material corp logoQuantum Materials Corporation (QMC) (OTCQB:QTMM) announces a new class of cadmium-free, non-REE, non-heavy metal tetrapod quantum dots (NHM-TPQD) developed to meet worldwide concerns regarding nanoparticle biocompatibility and sustainability.

QMC can produce industrial scale quantities of NHM-TPQD using proprietary continuous flow chemistry processes with over 90% tetrapod shape and size uniformity, unmatched in the industry. The new availability of a reliable supply of high quantities of uniform and low cost non-heavy metal tetrapod quantum dots will spur development of products and applications in next-generation displays, sensors, biomedical research, diagnostics and drug delivery, security and conductive inks, solid-state lighting (SSL) and photovoltaic solar cells, currently under development by QMC subsidiary Solterra Renewable Technologies.

Quantum dots in biomedical imaging are unique fluorescent probes with advantages over dyes and other fluorophores. QMC has made improvements in quantum dot brightness (high quantum yield), photostability for longer sample lifetime, high uniformity, narrow band, wide spectrum, and tunable emission spectrum. According to a 2012 market research report by Global Industry Analyst, Inc., the total market for Global BioImaging Technologies in 2017 is forecast to reach $34.7 billion.

In 2011, Quantum Materials and NanoAxis LLC pioneered a Joint Alliance to develop Tetrapod Quantum Dot based Cancer diagnostic kits and theranostic applications including Alzheimer’s, Type 1 and Type 2 Diabetes, Breast Cancer and Major Depression.

Quantum Materials CEO and Founder, Mr. Stephen Squires commented, “While our cadmium-based high-brightness tetrapod quantum dots are unparalleled in photovoltaic solar cell applications and especially for commercializing high value, small quantity in vitro research and lab applications, our non-heavy metal tetrapod quantum dot answers the world’s ecological and in vivo human toxicological concerns for mass-produced QD in the biotech and other fields of science.”

Quantum Materials Corporation is poised to become the world’s largest manufacturer of quantum dots by scaling production to multiple kilograms per day in 2013. QMC’s production is not subject to any other manufacturer’s patents and QMC is free to joint venture and to license its technology.

Mr. Squires is speaking at the CHI Emerging Diagnostics Partnering Forum in San Francisco this week on quantum dot applications in the next generation of diagnostic assays, multiplexed drug delivery platforms and handheld POC devices. Quantum Materials Corporation is then exhibiting at the CHI Molecular Med Tri-Conference on February 13-14, Booth 622.

About Quantum Materials Corporation and its subsidiary, Solterra Renewable Technologies

QUANTUM MATERIALS CORPORATION, INC. has a steadfast vision that advanced technology is the solution to the most challenging of global issues. Quantum Materials Corporation is devoted to the deployment of technologies to invigorate the development of disruptive solutions through cost reduction and moving laboratory discovery to commercialization with volume manufacturing methods to establish a growing line of innovative high performance products.

New Material Promises Better Solar Cells


QDOTS imagesCAKXSY1K 8Researchers at the Vienna University of Technology show that a recently discovered class of materials can be used to create a new kind of solar cell.

 

Researchers New Solar Cell

Elias Assmann (left) and Karsten Held (right) demonstrate the idea behind the new solar cell: Light is absorbed by a layered structure, free charge carrieres are produced and electric current starts to flow.

Single Layer Solar Cells

Sunlight is converted into electrical current in a layered structure.

Single atomic layers are combined to create novel materials with completely new properties. Layered oxide heterostructures are a new class of materials, which has attracted a great deal of attention among materials scientists in the last few years. A research team at the Vienna University of Technology, together with colleagues from the USA and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells.

Discovering New Material Properties in Computer Simulations “Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own”, says Professor Karsten Held from the Institute for Solid State Physics, Vienna University of Technology. In order to design new materials with exactly the right physical properties, the structures were studied in large-scale computer simulations. As a result of this research, the scientists at TU Vienna discovered that the oxide heterostructures hold great potential for building solar cells.

Turning Light into Electricity The basic idea behind solar cells is the photoelectric effect. Its simplest version was already explained by Albert Einstein in 1905: when a photon is absorbed, it can cause an electron to leave its place and electric current starts to flow. When an electron is removed, a positively charged region stays behind – a so called “hole”. Both the negatively charged electrons as well as the holes contribute to the electrical current.

“If these electrons and holes in the solar cell recombine instead of being transported away, nothing happens and the energy cannot be used”, says Elias Assmann, who carried out a major part of the computer simulations at TU Vienna. “The crucial advantage of the new material is that on a microscopic scale, there is an electric field inside the material, which separates electrons and holes.” This increases the efficiency of the solar cell.
Two Isolators Make a Metal The oxides used to create the material are actually isolators. However, if two appropriate types of isolators are stacked, an astonishing effect can be observed: the surfaces of the material become metallic and conduct electrical current. “For us, this is very important. This effect allows us to conveniently extract the charge carriers and create an electrical circuit”, says Karsten Held. Conventional solar cells made of silicon require metal wires on their surface to collect the charge carriers – but these wires block part of the light from entering the solar cell.

Not all photons are converted into electrical current with the same efficiency. For different colors of light, different materials work best. “The oxide heterostructures can be tuned by choosing exactly the right chemical elements”, says Professor Blaha (TU Vienna). In the computer simulations, oxides containing Lanthanum and Vanadium were studied, because that way the materials operate especially well with the natural light of the sun. “It is even possible to combine different kinds of materials, so that different colors of light can be absorbed in different layers of the solar cell at maximum efficiency”, says Elias Assmann.

Putting Theory into Practice The team from TU Vienna was assisted by Satoshi Okamoto (Oak Ridge National Laboratory, Tennessee, USA) and Professor Giorgio Sangiovanni, a former employee of TU Vienna, who is now working at Würzburg University, Germany. In Würzburg, the new solar cells will now be build and tested. “The production of these solar cells made of oxide layers is more complicated than making standard silicon solar cells. But wherever extremely high efficiency or minimum thickness is required, the new structures should be able to replace silicon cells”, Karsten Held believes.

NREL and Partners Demonstrate Quantum Dots that Assemble Themselves


Surprising breakthrough could bolster quantum photonics, solar cell efficiency

February 8, 2013

QDOTS imagesCAKXSY1K 8Scientists from the U.S. Department of Energy’s National Renewable Energy Laboratory and other labs have demonstrated a process whereby quantum dots can self-assemble at optimal locations in nanowires, a breakthrough that could improve solar cells, quantum computing, and lighting devices.

 

A paper on the new technology, “Self-assembled Quantum Dots in a Nanowire System for Quantum Photonics,” appears in the current issue of the scientific journal Nature Materials.

Quantum dots are tiny crystals of semiconductor a few billionths of a meter in diameter.  At that size they exhibit beneficial behaviors of quantum physics such as forming electron-hole pairs and harvesting excess energy.

The scientists demonstrated how quantum dots can self-assemble at the apex of the gallium arsenide/aluminum gallium arsenide core/shell nanowire interface. Crucially, the quantum dots, besides being highly stable, can be positioned precisely relative to the nanowire’s center. That precision, combined with the materials’ ability to provide quantum confinement for both the electrons and the holes, makes the approach a potential game-changer.

Electrons and holes typically locate in the lowest energy position within the confines of high-energy materials in the nanostructures. But in the new demonstration, the electron and hole, overlapping in a near-ideal way, are confined in the quantum dot itself at high energy rather than located at the lowest energy states. In this case, that’s the gallium-arsenide core. It’s like hitting the bulls-eye rather than the periphery.

The quantum dots, as a result, are very bright, spectrally narrow and highly anti-bunched, displaying excellent optical properties even when they are located just a few nanometers from the surface – a feature that even surprised the scientists.

“Some Swiss scientists announced that they had achieved this, but scientists at the conference had a hard time believing it,” said NREL senior scientist Jun-Wei Luo, one of the co-authors of the study. Luo got to work constructing a quantum-dot-in-nanowire system using NREL’s supercomputer and was able to demonstrate that despite the fact that the overall band edges are formed by the gallium Arsenide core, the thin aluminum-rich barriers provide quantum confinement both for the electrons and the holes inside the aluminum-poor quantum dot. That explains the origin of the highly unusual optical transitions.

Several practical applications are possible. The fact that stable quantum dots can be placed very close to the surface of the nanometers raises a huge potential for their use in detecting local electric and magnetic fields. The quantum dots also could be used to charge converters for better light-harvesting, as in the case of photovoltaic cells.

The team of scientists working on the project came from universities and laboratories in Sweden, Switzerland, Spain, and the United States.

NREL is the U.S. Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy, LLC.

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Visit NREL online at www.nrel.gov

The Rise of the Nanoco (NANO) and the efficiency game – Quantum Dots in Solar, LED’s and LCD TV’s


Original article By Charlie Hayter PUBLISHED: 23 Jan 2013 @ 14:41

QDOTS imagesCAKXSY1K 8Note to Readers: “Nanoco” has been making some significant headlines recently. As noted in this article, there are some very good reasons for that, most recently, the announcement of the JV Alliance with DOW Chemical (Electronics). It is noted that there are still some significant risks in both the cost and scale-up inputs yet to come, as Nanoco (and others) move forward to scalable commercialization. Another significant risk is the mass production of heavy-metal free (cadmium) QD’s.   There seems to be an assumption as to a “cost” per gram that will still remain high and a process of manufacture that will “limit” the amount of nano-materials available to be incorporated into existing product development and commercialization.

We wonder however, like the comments of “Ken G.” at the end of this article, if indeed there are not “others” out there developing H.M free, low cost and mass producible Quantum Dots that will dramatically change the risk/ reward investment equation. Cheers!   BWH

Quantum Dots were discovered in 1980 by Alexei Ekimov, and have been playing an ever more important role in tech advances for televisions and solar cells, as well as a host of applications further away from commercialisation. The unique properties of quantum dots allow the photonic emissions to be tuned by the size of the dot and this has meaningful benefits to solar cell efficiency and LCD power consumption, as well as bringing the colour array of LCD/LED into the OLED league potentially at a much lower cost. There are a number of Companies involved in this space, Nanosolar (privately held) – focuses on Quantum Dot CIS Solar Cells, Nanosys & QD Vision (privately held) concentrating on TV displays and LEDs, and Nanoco (LSE:NANO) concentrating on solar with Tokyo Electron and TV displays with other unnamed Asian partners, which announced today its licensing agreement for distributing cadmium free quantum dots for the display market with DOW Chemical.

For Nanoco, this follows on from stake building by Henderson pre-Christmas, an initiation of coverage by Liberum with a TP of 160p on the 16th of Jan and upgrade today to 260p, an upgrade today by Canaccord to 265p and finally the first commercial display exhibited by Sony in conjunction with QD Vision at the start of this year.

Announcement and Take

Nanoco announced today a global licensing agreement whereby DOW Electronic Materials will have exclusive worldwide right to market and manufacture Nanoco’s Quantum dots for use in electronic displays, with Nanoco receiving an undisclosed royalty payment. DOW Electronic Material will build a facility in Asia. The capacity has not been disclosed.

It looks like the Runcorn facility will be put on hold and it is not clear whether electronic displays include Diodes alongside the LCD/LED segment.

Quantum Dots – A bit of science

Quantum dots are small crystals that emit light of varying colours depending on the size of the crystal. Generally the smaller the crystal, the harder it is to produce, and the higher the frequency it emits. So a small crystal will emit blue light and a larger one red light.

Applications 1 – Solar

The major technological battle in solar has been between the flexible, low weight and efficiency thin Film vs the cumbersome, higher efficiency Crystalline silicon. In 2008 Thin Film was all the rage with sky high Polysilicon prices and bets were on Thin Film gradually taking market share. Firstsolar had a cost per Watt that was 50% below polysilicon competitors and an efficiency of c.10%, compared to crystalline silicon technologies at roughly 15%. Now, the cost per Watt for Firstsolar sits at around $0.67 and the average efficiency of its modules at around 12.7% compared to crystalline silicon technology at approximately $0.75 and an efficiency of 16-17%.

The relative catch up of crystalline silicon in terms of cost has been mainly due to the falling polysilicon price coupled with the increasing economies of scale. Breakthroughs, in terms of efficiency, have been made with anti-reflective layers (stopping light bouncing of the cell surface – analogous to a cats-eye), selective doping, and thinner printing of the silver conductors on the cell surface or burying them altogether.  However the theoretical limit to single junction solar cells/modules is constrained by the Schockley-Quiesser limit to 33%.

The Schockley-Queisser limit comes about due to the solar spectrum, i.e. the light emitted from the sun and the bandgap of the material being used to convert it to electricity. With our sun, the optimum bandgap is about 1.4eV, and silicon is chosen due to its close approximation to that, 1.1eV, also taking into account its properties as a conductor. The theoretical limit with single junction crystalline silicon is about 29% as the bandgap doesn’t match the optimum point due to the trade off for better conductivity and less electron hole recombination. Simply put, in standard solar cells, a high energy photon comes in 2eV and kicks off an electron, leaving the other 0.9eV as heat and so limiting the efficiency.

There are a few methods to counteract this, such as multi-junction cells. They (mostly GaAs) provide band gaps across at multiple points across the spectrum to maximise the theoretical efficiency. Essentially they vertically stack different materials with different bandgaps to capture more of the light. An infinitely layered multi-junction cell has a theoretical limit of 86%. At the moment these cells are only used in satellites because of their high cost due to the complex process of depositing multiple layers.

There is another way of breaching the single junction limit of 33% by using Quantum Dots, as they can emit multiple electrons from a single photon. As such the theoretical efficiency can be increased to 42% for single junction solar modules. Nanosolar, a Californian based Google funded venture, has reached a laboratory efficiency of 17.1% with its CIGS (Copper Indium Gallium Di-Selenide) product, but bear in mind laboratory efficiencies take 5 plus years to translate 50% of their advances into commercial production.

Application 2: TV’s

The turmoil that has been the history of televisions is a story of ever more violent upheavals and rapid technological shifts. Cathode rays have been made obsolete by plasma’s and LCD’s, and now flexible OLED’s have set the challenge to hybrid LED/LCD’s.

LCD’s provided lower costs, thinner screens and better colours compared to CRT’s, and OLED’S did the same to LCD’s whilst eliminating the backlight . Finally hybrid LCD/LED TV’s, either backlit or side-lit with their respective advantages, incorporated the low energy consumption by using LED’s whilst maintaining the filtering element of the LCD crystal displays. The threat of OLED’s and its better colour rendering has reared its head, and is being sold as a premium due to its cost but isn’t gaining market share.

The race has all been about slimmer, sexier and more extras – like a combination catwalk and page 3 model. LCD’s and their hybrid LED/LCD’s have an estimated 70% market share in 2012 from less than 5% in 2005. OLEDS have started to make an appearance but are priced at a significant premium – for example the 55inch Samsung OLED sells for just over £6000 compared to LCD’s and their variants at £1000-1500. Even though there is a distinctive price premium, OLED’s are easily degraded by water and continued use – specifically with the blue colour OLED (losing 50% of effectiveness over five years at eight hrs usage per day). Quantum Dots also have their problems, although not insurmountable, by being oxidised readily in air.

The plan for OLED’S is to follow the cost curve lower, but yet again the disruptive element of quantum dots could change the game. The concept was displayed earlier this month by Sony, where a gallium nitride blue LED light passes through a layer of Quantum dots and then out via the LCD display. The advantages over the traditional side-lit or backlit white LED being a colour scale comparable with OLED’s, power savings and potential cost savings – so an OLED quality TV that doesn’t break the bank. Another advantage of the quantum dot model is that old LCD fabs can be modified to include it instead of a dramatic overhaul with specialised deposition equipment as in the case of OLED’s. Clearly this is where DOW is positioning itself.

Application 3: LED’s

LED’s are gaining market share across the world in the traditional lighting segment as well as being an integral part of the LCD/LED hybrid display. At present white colour light is made in two ways, either through phosphorous doped blue LED’s that stretch out light spectrum to give the appearance of white light, or by combining Red, Green and Blue diodes. The problem with the RGB combination is that it costs a lot – 3 diodes instead of one that is modified, whilst phosphor doping leaves a large spike in the blue end of the visible spectrum and gives an unnatural hue to end viewing.

You’ve guessed it, Quantum dots can be married with the blue gallium nitride diodes, to give off truer colour. Nanosys simply has a Quantum dot lens that covers the blue light and gives off more natural light.

With TV’s however, the plan is to incorporate the Quantum Dots as a film across the back of the TV. Most broker notes haven’t highlighted this, but surely it would be better to just have Quantum Dot enhanced LED’s in the background. This could have effects on sales/volumes estimated so far.

Nanoco

The Company is Manchester based spin-off of its home city’s university, alongside Imperial College. The Market cap is nearing £300m with 2011 revenues of £2.6m, so is this premium justified or is the Company too hot to touch right now – are we back in the days of Fuel Cell Companies, such as ITM in 2006-7.

Financials

The problem is placing an estimate on revenues. At present the Company sells most of its product as milestone payments for about £2m per Kg. Most brokers are estimating prices in the region of £200k-50k per Kg declining through to 2017, with a volume ramp increased from 100-250kg in 2014 through to 12,000kg – or FY ‘17 revenues of £150m after taking into account an estimated 25% royalty payment. As for earnings, a pie in the sky guess of 30%, meaning a forward ’17 multiple of 6.7.

So what does this mean for market share of display televisions. According to the Company an estimate of 0.7g of quantum dots per 60 inch TV can be used – so a 40% market penetration in 2018 would require 12,000kg – which is what Dow Chemicals two largest clients, LG and Samsung, roughly hold in the high end TV market. Definitely plausible, but a lot of assumptions on price, royalty and production.

Let’s look at it another way – with yet another load of estimates. What about the replacement costs for what’s out there already. Estimating the LED cost for a 40inch TV (about 750 LEDs) and using low range costs off various websites, the total white SMD (surface mounted design) LED costs would be roughly $23. With blue LEDs the cost would be $8 and the quantum dots $28 – assuming £50,000 per Kg and not including assembly. So a bit of an extra cost but nothing compared to the CAPEX required for OLED’s and yet the same visual result– and it’s not clear whether this 0.7g estimate is for entire films of QD’s or for coated or “lensed” diode’s. Just consider this a thought experiment before getting lambasted on the bulletin boards.

Nanoco’s USP for mitigating risks

There are three major linked risks to Nanoco: Competition, scaling production and the Cadmium free saga.

Nanoco has produced Cadmium free Quantum Dots by complying with the ROHS (Restriction of Hazardous Materials Directive, which have given it a head start with regards to competitors QD Vision and Nanosys who don’t. Samsung have abandoned their Cadmium quantum dot campaign for this reason.

The issue with scaling a nascent product could also restrict market take up. Nanoco says it’s molecular seeding process is more appropriate than its competitors dual injection, as temperature control is more easily maintained – but you have to take their word for that, and DOW has. So it looks like Nanoco has won the first round.

Industry News and potential M&A

The solar space has picked up yet again with a whole new wave of MA. Q-cells and its Hanergy Hanwha sale, Hanergy and Miasole and its stake in Apollo solar, and finally Oerlikon buyout by Tokyo Electron, who have the agreement for a solar ink with Nanoco. But Nanoco’s ink has only reached efficiencies of 8% in respect to Nanosolar’s NREL approved 17%. So with solar it’s probably long way off, leaving the lighting and the screen display market as the most immediately cash generative.

You have to ask the question will it be taken out? Private equity has both of its major competitors. Diode companies, such as Cree, Epistar and Osram, have a lot to lose by not being a first mover in this market, but they’re electronics Companies not Chemical Companies. Furthermore, Dow has already taken the bait saying “we want this product” proving its tastiness to the majors – and could make more moves for further distributorship rights, i.e. to LED makers if the present agreement doesn’t include it.

Conclusion

A risky nascent tech that has clearly huge market potential: Richly priced but for these reasons. But strategically it is a sitting duck for Chemical Companies, and, most likely for Dow to consolidate, although this could be heavily premature. However, the news of DOWS involvement is a strong catalyst for earlier revenue generation as well as being a confirmation of the technologies scalability and potential, although the lack of clarity on the specifics of the deal are somewhat irksome. Bear in mind the potential for scale up delays on the downside and lack of revenue visibility, and on the upside, announcements for the LED market primarily as well as the solar space. Looks like a buy, hold and buy on dips if or as enthusiasm wanes – but this is a highly speculative stock with uncertainties galore, so something for the growth section of your portfolio that you can afford to lose – maybe prudent to wait for a pull back before entry, but then you might miss out.

Ken G says:

I believe one company you left off your list has the solutions to many of the issues regaurding mass productionn and scale of economy.They are a publically listed company QTMM and were recently covered by Frost and Sullivan recieving the “2012 North American Enabling Technology Award for Advanced Quantum Dot Manufacturing”.

Quantum Materials Corp First-Tetrapods Synthesis with over 92%> Full Shape First-Tetrapods with over 92% Uniformity of Size First-Tetrapods w/precise control of arm width & length First-Tetrapods Eco-Friendly Green Synthesis First-Tetrapods Continuous Flow Chemistry Process First-Tetrapods Mass Production by Continuous Flow Wide Variety of Group II-VI Tetrapods; Cd or Cd-Free Dec. 2012: New Tetrapod with 80%> Quantum Yield Best Tetrapod for Commercializing New Applications Best Company for Nanotech Joint Venture Partnering Proprietary QD Printed Electronics Technologies Precision printed lithography, gravure, inkjet printing Roll to Roll QD Printing at high speed on flexible substrates

QMC is the parent company for Solterra Renewable Technologies who are developing 3rd generation solar using quantum dots..

Solterra Renewable Technologies Solterra Renewable Technologies developing Non-REE Flexible Thin-Film Photovoltaic Tetrapod Quantum Dot Solar Plants. Our objective is to become the first bulk manufacture of high quality tetrapod quantum dots and the first solar cell manufacturer to be able to offer a solar electricity solution that competes on a non-subsidized basis with the price of retail electricity in key markets in North America, Europe, the Middle East and Asia.