CdTe ink makes high-efficiency solar cell


Chicago CdE pic1Cadmium telluride nanocrystal colloids could be used as the photovoltaic “ink” in solar cells, according to new experiments by researchers at the National Renewable Energy Laboratory and the University of Chicago. Devices made using CdTe layers as thin as just 330 nm have a sunlight-to-power conversion of efficiency of 10% while those made with 550 nm thick layers have an efficiency of more than 11%. They also boast an impressive blue light response of nearly 80% external quantum efficiency – something that allows for improved photocurrent from these cells.

Thin-film photovoltaic materials could be alternatives to traditional silicon-based solar-cell materials because they absorb sunlight more efficiently – thanks to the fact that they have direct rather than indirect bandgaps. This means that less material, weight for weight, is needed to absorb the same amount of solar radiation. What is more, thin-film photovoltaics, such as cadmium telluride, can be easily and cheaply deposited onto a wide range of flexible and rigid substrates in solution.

Chicago CdE pic1

Spheres, faceted nanocrystals and tetrapods

There is a problem, however, in that the power-conversion efficiencies of thin-film materials that have been processed from solution are typically lower than those produced by traditional vapour deposition techniques.

Now, a team led by Dmitri Talapin of Chicago and Joseph Luther at NREL has succeeded in synthesizing CdTe inks from solutions of nanocrystals that have controllable shapes, ranging from spheres to tetrapods, and controllable crystallographic phases: wurtzite and zincblende. The researchers found that the best performing solar-cell devices are those containing tetrapodal-shaped nanocrystals in the wurtzite phase. Following a relatively low-temperature short anneal, these crystals undergo a critical phase change from wurtzite to zincblende that coincides with the small grain soluble nanocrystals growing into large grain, photovoltaic quality, CdTe.

Layer-by-layer approach

“Rather than depositing the whole CdTe layer at once, we use a layer-by-layer approach to build up a very thin layer of the CdTe and control the grain growth,” explains team member Ryan Crisp, graduate student at the Colorado School of Mines. “We then deposit more nanocrystals and repeat the process until we reach the desired layer thickness.”

As the nanocrystals change phase and sinter (or grow) together, they form polycrystalline films, he adds. These films are unique in that they are exceptionally smooth and uniform (compared with films that are produced by traditional sublimation methods). “This means that further layers have a ‘nice’ surface on which we can deposit without fear of encountering short-circuits caused by irregularities and defects,” he tells nanotechweb.org.

“The crystal grains in our material extend from the top to the bottom in a finished device, allowing us to efficiently extract charge carriers (in this case photoexcited electrons) from it. We are able to do this since the electrons do not encounter many grain boundaries – something that minimizes their chance of being ‘lost’ to defect traps as they travel through the structure.”

Higher-efficiency, lower-cost devices

Solar cells made from the CdTe ink boast a sunlight-to-power conversion efficiency of 10–12%. This value might be further improved by placing the ink on the right type of substrate. “By employing this inexpensive solution-processed ink (instead of the more expensive, and slower throughput thin-film photovoltaic materials produced by sublimation), we can make potentially higher-efficiency, lower-cost devices,” says Crisp. “We explored several device structures and found that the ink-based films perform better in a simple ITO/CdTe/ZnO/Al structure rather than the traditional structure with CdS and ZnTe contacts.”

The main limiting factor to improving device efficiency is increasing the open circuit voltage. “We now plan on improving the quality of the ITO/CdTe interface (used in our highest efficiency device) to do this – and in particular by better controlling the energy levels (that is the band alignment) of the materials at this interface,” adds Crisp.

The new photovoltaic ink is described in ACS Nano

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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!”

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.

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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”

Genesis Nanotech News: Latest Updates


QDLED 08_Bulovic_QDs_inLiquidSolutionsGenesis Nanotech: Latest News & Updates in Nanotechnology

U of Maryland Researchers Discover New synthesis Method: Could Impact the Futures of Nanostructures, Clean Energy

 

 

New Patent Issued to Samsung for Quantum Dot Organic Light Emitting Device (QDLED)

 

 

Simpler process to grow germanium nanowires could improve lithium ion batteries

 

 

Nanotechnology will leapfrog development.|Hiru News Official Web Site|Sri Lanka

KAUST: No Water, Mechanical, Automated, Dusting Device (NOMADD) for Solar Panels


KAUST Solar ic8dbMM9X_FMPublished on Jun 23, 2014

How do you remove the “dust” from hundreds of acres of Solar Panels? (Video)

 

The No Water, Mechanical, Automated, Dusting Device for photovoltaic installations (NOMADD) effectively removes dust without requiring any water or labor. This environmentally friendly technology enables more widespread use of solar photovoltaics in arid regions and helps to conserve the Earth’s water resources and harness the full potential of solar energy.

nomadd-solar-robot-no-water-1_jpg_650x0_q85_crop-smart

This technology is part of KAUST’s technology commercialization program that seeks to stimulate development and commercial use of KAUST-developed technologies. For more information, contact us at IP@kaust.edu.sa.

New $AUD30 M Research Facility at RMIT University in Melbourne


A new $AUD30 million research facility at RMIT University in Melbourne, Australia, will drive cutting-edge advances in micro- and nano-technologies.

RMIT University’s $AUD30 million MicroNano Research Facility.

The MicroNano Research Facility (MNRF) will bring to Australia the world’s first rapid 3D nanoscale printer and will support projects that span across the traditional disciplines of physics, chemistry, engineering, biology and medicine.

The City campus facility will be launched by Vice-Chancellor and President, Professor Margaret Gardner AO, on Wednesday, 27 August.

Professor Gardner said the opening of the state-of-the-art laboratories and clean rooms was the start of an exciting new chapter in cross-disciplinary nano research.

Aus micro nano zqnydqgs2c8m1

“At the heart of the MicroNano Research Facility’s mission is bringing together disparate disciplines to enable internationally-leading research activity,” she said.

“RMIT has long been a pioneer in this field, opening Australia’s first academic clean rooms at the Microelectronics and Materials Technology Centre in 1983.

“Over three decades later, this investment in the world-class MNRF will enable RMIT’s leading researchers to continue to break new ground and transform the future.”

Among the equipment available to researchers in the 1200 square metre facility will be the world’s first rapid 3D nanoscale printer, capable of producing thousands of structures – each a fraction of the width of a human hair – in seconds.

Designed by architects SKM Jacobs, the MNRF also offers researchers access to more than 50 cutting-edge tools, including focused ion beam lithography with helium, neon, and gallium ion beams to enable imaging and machining objects to 0.5 nm resolution – about 5 to 10 atoms.

Director of the MNRF, Professor James Friend, said 10 research teams would work at the new facility on a broad range of projects, including:

  • building miniaturised motors – or microactuators – to retrieve blood clots from deep within the brain, enabling minimally invasive neurological intervention in people affected by strokes or aneurysms;
  • improving drug delivery via the lungs through new techniques that can atomise large biomolecules – including drugs, DNA, antibodies and even cells – into tiny droplets to avoid the damage of conventional nebulisation;
  • developing innovative energy harvesting techniques that change the way batteries are recharged, using novel materials that can draw on the energy generated simply by people walking around; and,
  • inventing ways to use water to remove toxins from fabric dyes, with new nanotechnologies that can facilitate the breaking down of those dyes with nanostructured catalysts.

“This facility is all about ensuring researchers have the freedom to imagine and safely realise the impossible at tiny scales and beyond,” Professor Friend said.

“Having access to purpose-designed laboratories and leading-edge equipment opens tremendous opportunities for RMIT and for those we collaborate with, enabling us to advance the development of truly smart technology solutions to some of our most complex problems.”

Laboratories in the MNRF will include:

  • Gas sensors laboratory
  • Metrology laboratory
  • Novel Fabrication laboratory
  • PC2 mammalian cell laboratory
  • Photolithography laboratory
  • Physical vapour deposition laboratory
  • Polydimethylsiloxane (PDMS) and nanoparticle laboratory
  • Wet etch laboratory
  • Support laboratory

The MNRF will be a key enabler of RMIT’s flagship Health Innovations Research Institute and Platform Technologies Research Institute.

A unique teaching facility will also be affiliated with the MNRF.

The Micro Nano Teaching Facility (MNTF) is the first of its kind in Australia, enabling undergraduate and postgraduate engineering student trainees to study clean room operations and micro-fabrication

Eco-Friendly ‘pre-fab nanoparticles’ Could Revolutionize Nano Manufacturing


 

Eco-Friendly Nano 49975

Eco-friendly ‘pre-fab nanoparticles’ could revolutionize nano manufacturing: UMass Amherst team invents a way to create versatile, water-soluble nano-modules

Amherst. MA | Posted on August 13th, 2014

 

A team of materials chemists, polymer scientists, device physicists and others at the University of Massachusetts Amherst today report a breakthrough technique for controlling molecular assembly of nanoparticles over multiple length scales that should allow faster, cheaper, more ecologically friendly manufacture of organic photovoltaics and other electronic devices. Details are in the current issue of Nano Letters.

Lead investigator, chemist Dhandapani Venkataraman, points out that the new techniques successfully address two major goals for device manufacture: controlling molecular assembly and avoiding toxic solvents like chlorobenzene. “Now we have a rational way of controlling this assembly in a water-based system,” he says. “It’s a completely new way to look at problems. With this technique we can force it into the exact structure that you want.”

Materials chemist Paul Lahti, co-director with Thomas Russell of UMass Amherst’s Energy Frontiers Research Center (EFRC) supported by the U.S. Department of Energy, says, “One of the big implications of this work is that it goes well beyond organic photovoltaics or solar cells, where this advance is being applied right now. Looking at the bigger picture, this technique offers a very promising, flexible and ecologically friendly new approach to assembling materials to make device structures.”

Eco-Friendly Nano 49975

 

Lahti likens the UMass Amherst team’s advance in materials science to the kind of benefits the construction industry saw with prefabricated building units. “This strategy is right along that general philosophical line,” he says. “Our group discovered a way to use sphere packing to get all sorts of materials to behave themselves in a water solution before they are sprayed onto surfaces in thin layers and assembled into a module. We are pre-assembling some basic building blocks with a few predictable characteristics, which are then available to build your complex device.”

“Somebody still has to hook it up and fit it out the way they want,” Lahti adds. “It’s not finished, but many parts are pre-assembled. And you can order characteristics that you need, for example, a certain electron flow direction or strength. All the modules can be tuned to have the ability to provide electron availability in a certain way. The availability can be adjusted, and we’ve shown that it works.”

The new method should reduce the time nano manufacturing firms spend in trial-and-error searches for materials to make electronic devices such as solar cells, organic transistors and organic light-emitting diodes. “The old way can take years,” Lahti says.

“Another of our main objectives is to make something that can be scaled up from nano- to mesoscale, and our method does that. It is also much more ecologically friendly because we use water instead of dangerous solvents in the process,” he adds.

For photovoltaics, Venkataraman points out, “The next thing is to make devices with other polymers coming along, to increase power conversion efficiency and to make them on flexible substrates. In this paper we worked on glass, but we want to translate to flexible materials and produce roll-to-roll manufactured materials with water. We expect to actually get much greater efficiency.” He suggests that reaching 5 percent power conversion efficiency would justify the investment for making small, flexible solar panels to power devices such as smart phones.

If the average smart phone uses 5 watts of power and all 307 million United States users switched from batteries to flexible solar, it could save more than 1500 megawatts per year. “That’s nearly the output of a nuclear power station,” Venkataraman says, “and it’s more dramatic when you consider that coal-fired power plants generate 1 megawatt and release 2,250 lbs. of carbon dioxide. So if a fraction of the 6.6 billion mobile phone users globally changed to solar, it would reduce our carbon footprint a lot.”

Doctoral student and first author Tim Gehan says that organic solar cells made in this way can be semi-transparent, as well, “so you could replace tinted windows in a skyscraper and have them all producing electricity during the day when it’s needed. And processing is much cheaper and cleaner with our cells than in traditional methods.”

Venkataraman credits organic materials chemist Gehan, with postdoctoral fellow and device physicist Monojit Bag, with making “crucial observations” and using “persistent detective work” to get past various roadblocks in the experiments. “These two were outstanding in helping this story move ahead,” he notes. For their part, Gehan and Bag say they got critical help from the Amherst Fire Department, which loaned them an infrared camera to pinpoint some problem hot spots on a device.

It was Bag who put similar sized and charged nanoparticles together to form a building block, then used an artist’s airbrush to spray layers of electrical circuits atop each other to create a solar-powered device. He says, “Here we pre-formed structures at nanoscale so they will form a known structure assembled at the meso scale, from which you can make a device. Before, you just hoped your two components in solution would form the right mesostructure, but with this technique we can direct it to that end.”

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This work at the Polymer-Based Materials for Harvesting Solar Energy is part of an EFRC supported by the U.S. DOE’s Office of Basic Energy Science.

 

Copyright © University of Massachusetts at Amherst

 

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