David Kirkpatrick

November 16, 2009

Beautiful nanotech image — photovoltaic solar cell

This is a nice gallery of nanotech images from New Scientist. Here’s the description from the series, “Chemist George Whitesides has collaborated with MIT and Harvard photographer-in-residence Felice Frankel to produce No Small Matter, a book of images of the micro and nanoworld.”

From the first image, my favorite:

Sun catchers

This is a close-up of the top side of a photovoltaic solar cell. The cell converts the energy from the sun’s photons into electrical energy by taking advantage of the photo-electric effect. This cell is made of a wafer of crystalline silicon.

Light is absorbed by the wafer and creates charge that is collected by silver conductor lines, shown in the image as the gold-coloured strip. The cell is coated with silicon nitride which acts as an anti-reflective surface, preventing light energy from bouncing away and giving the cell its blue-violet colour.

Rather than attaching solar panels to our roofs, recent research suggests that in the future we could paint solar cells on to our houses, removing the need to rely on expensive silicon wafers.

(Image: Felice Frankel)

May 30, 2009

Solar cells and lasers

Filed under: Business, Science, Technology — Tags: , , , , , — David Kirkpatrick @ 12:15 pm

Here’s the latest news in solar — using lasers to improve solar cells.

The release:

Lasers are making solar cells competitive

Solar electricity has a future: It is renewable and available in unlimited quantities, and it does not produce any gases detrimental to the climate. Its only drawback right now is the price: the electric power currently being produced by solar cells in northern Europe must be subsidized if it is to compete against the household electricity generated by traditional power plants. At “Laser 2009” in Munich, June 15 to 18, Fraunhofer researchers will be demonstrating how laser technology can contribute to optimizing the manufacturing costs and efficiency of solar cells. 

Cell phones, computers, MP3 players, kitchen stoves, and irons all have one thing in common: They need electricity. And in the future, more and more cars will also be fuelled by electric power. If the latest forecast from the World Energy Council WEC can be believed, global electricity requirements will double in the next 40 years. At the same time, prices for the dwindling resources of petroleum and natural gas are climbing.

“Rising energy prices are making alternative energy sources increasingly cost-effective. Sometime in the coming years, renewable energy sources, such as solar energy, will be competitive, even without subsidization,” explains Dr. Arnold Gillner, head of the microtechnology department at the Fraunhofer Institute for Laser Technology in Aachen, Germany. “Experts predict that grid parity will be achieved in a few years. This means that the costs and opportunities in the grid will be equal for solar electricity and conventionally generated household electricity.” Together with his team at the Fraunhofer Institute for Laser Technology ILT in Aachen, this researcher is developing technologies now that will allow faster, better, and cheaper production of solar cells in the future. “Lasers work quickly, precisely, and without contact. In other words, they are an ideal tool for manufacturing fragile solar cells. In fact, lasers are already being used in production today, but there is still considerable room for process optimization.” In addition to gradually improving the manufacturing technology, the physicists and engineers in Aachen are working with solar cell developers – for example, at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg – on new engineering and design alternatives.

New production technologies allow new design alternatives

At “Laser 2009” in Munich, the researchers will be demonstrating how lasers can drill holes into silicon cells at breathtaking speed: The ILT laser system drills more than 3,000 holes within one second. Because it is not possible to move the laser source at this speed, the experts have developed optimized manufacturing systems which guide and focuses the light beam at the required points. “We are currently experimenting with various laser sources and optical systems,” Gillner explains. “Our goal is to increase the performance to 10,000 holes a second. This is the speed that must be reached in order to drill 10,000 to 20,000 holes into a wafer within the cycle time of the production machines.”

The tiny holes in the wafer – their diameter is only 50 micrometers – open up undreamt-of possibilities for the solar cell developers.  “Previously, the electrical contacts were arranged on the top of the cells. The holes make it possible to move the contacts to the back, with the advantage that the electrodes, which currently act as a dark grid to absorb light, disappear. And so the energy yield increases. The goal is a degree of efficiency of 20 percent% in industrially-produced emitter wrap-through (EWT) cells, with a yield of one-third more than classic silicon cells,” Gillner explains. The design principle itself remains unchanged: In the semi-conductor layer, light particles, or photons, produce negative electrons and positive holes, each of which then wanders to the oppositely poled electrodes. The contacts for anodes and cathodes in the EWT cells are all on the back, there is no shading caused by the electrodes, and the degree of efficiency increases. With this technique, it may one day be possible to use unpurified “dirty” silicon to manufacture solar cells that have poorer electrical properties, but that are cheaper. 

Drilling holes into silicon cells is only one of many laser applications in solar cell manufacturing. In the EU project Solasys – Next Generation Solar Cell and Module Laser Processing Systems – an international research team is currently developing new technologies that will allow production to be optimized in the future. ILT in Aachen is coordinating the six million euro project. “We are working on new methods that make the doping of semiconductors, the drilling and the surface structuring of silicon, the edge isolation of the cells, and the soldering of the modules more economical,” project coordinator Gillner explains. For example, “selective laser soldering” makes it possible to improve the rejection rates and quality of the contacting, and so reduce manufacturing costs. Until now, the electrodes were mechanically pressed onto the cells, and then heated in an oven. “But silicon cells often break during this process,” Gillner knows. “Breakage is a primary cost factor in production.” On the other hand, however, with “selective laser soldering” the contacts are pressed on to the cells with compressed air and then soldered with the laser. The mechanical stress approaches zero and the temperature can be precisely regulated. The result: Optimal contacts and almost no rejects.

Laser technology means more efficient thin film cells

Laser technology is also helping to optimize the manufacture of thin film solar cells. The extremely thin film packages made of semiconducting oxide, amorphous silicon, and metal that are deposited onto the glass panels still have a market share of only ten percent. But as Gillner knows, “This could be higher, because thin film solar cells can be used anywhere that non-transparent glass panels can be mounted, for example, on house facades or sound-insulating walls. But the degrees of efficiency are comparable low at five to eight percent, and the production costs are comparatively high.” The laser researchers are working to improve these costs. Until now, the manufacturers have used mechanical methods or solid-state lasers in the nanosecond range in order to structure the active layers on the glass panels. In order to produce electric connections between the semiconductor and the metal, grooves only a few micrometers wide must be created. At the Fraunhofer-Gesellschaft booth at “Laser 2009” the ILT researchers will be demonstrating a 400-watt ultrashort pulse laser that processes thin-film solar modules ten times faster than conventional diode-pumped solid-state lasers. “The ultrashort pulse laser is an ideal tool for ablating thin layers: It works very precisely, does not heat the material and, working with a pulse frequency of 80 MHz, can process a 2-by-3 meter glass panel in under two minutes,” Gillner reports. “The technology is still very new, and high-performance scanning systems and optical systems adapted to the process must be developed first. In the medium term, however, this technology will be able to reduce production costs.”

The rise of laser technology in solar technology is just taking off, and it still has a long way to go. “Lasers simplify and optimize the manufacture of classic silicon and thin-film cells, and they allow the development of new design alternatives,” Gillner continues. “And so laser technology is making an important contribution towards allowing renewable energy sources to penetrate further into the energy market.”

May 22, 2009

Sanyo sets solar conversion record

Filed under: Business, Science, Technology — Tags: , , , , — David Kirkpatrick @ 3:01 pm

Via KurzweilAI.net — Sanyo broke its own record for solar cell energy conversion efficiency.

SANYO Breaks Solar Cell Record
Azonanotechnology, May 21, 2009

SANYO Electric has broken its own record for the world’s highest energy conversion efficiency in practical size (100 cm2 or more) crystalline silicon-type solar cells, achieving a efficiency of 23.0% (until now 22.3%) at a research level for its proprietary HIT solar photovoltaic cells.

Read Original Article>>

May 1, 2009

Nanotubes seeing the rainbow

Nanotubes that can “see” the entire spectrum offer a lot of possibilities in terms of application, including improved solar cells.

The release:

Sandia researchers construct carbon nanotube device that can detect colors of the rainbow

LIVERMORE, Calif. — Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes.

Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length.

The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model.

When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube.

“In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule,” says Sandia researcher Xinjian Zhou. “We placed the nanotube transistor behind the molecule—a more efficient design.”

Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, “Color Detection Using Chromophore-Nanotube Hybrid Devices,” in the journal Nano Letters.

The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2—about 3 percent of the density of sunshine reaching the ground. “Because the dye is so close to the nanotube, a little change turns into a big signal on the device,” says Zhou.

The research is in its second year of internal Sandia funding and is based on Léonard’s collaboration with the University of Wisconsin to explain the theoretical mechanism of carbon nanotube light detection. Léonard literally wrote the book on carbon nanotubes—The Physics of Carbon Nanotubes, published September 2008.

Léonard says the project draws upon Sandia’s expertise in both materials physics and materials chemistry. He and Wong laid the groundwork with their theoretical research, with Wong completing the first-principles calculations that supported the hypothesis of how the chromophores were arranged on the nanotubes and how the chromophore isomerizations affected electronic properties of the devices.

To construct the device, Zhou and Krafcik first had to create a tiny transistor made from a single carbon nanotube. They deposited carbon nanotubes on a silicon wafer and then used photolithography to define electrical patterns to make contacts.

The final piece came from Vance and Zifer, who synthesized molecules to create three types of chromophores that respond to either the red, green, or orange bands of the visible spectrum. Zhou immersed the wafer in the dye solution and waited a few minutes while the chromophores attached themselves to the nanotubes.

The team reached their goal of detecting visible light faster than they expected—they thought the entire first year of the project would be spent testing UV light. Now, they are looking to increase the efficiency by creating a device with multiple nanotubes.

“Detection is now limited to about 3 percent of sunlight, which isn’t bad compared with a commercially available digital camera,” says Zhou. “I hope to add some antennas to increase light absorption.”

A device made with multiple carbon nanotubes would be easier to construct and the resulting larger area would be more sensitive to light. A larger size is also more practical for applications.

Now, they are setting their sites on detecting infrared light. “We think this principle can be applied to infrared light and there is a lot of interest in infrared detection,” says Vance. “So we’re in the process of looking for dyes that work in infrared.”

This research eventually could be used for a number of exciting applications, such as an optical detector with nanometer scale resolution, ultra-tiny digital cameras, solar cells with more light absorption capability, or even genome sequencing. The near-term purpose, however, is basic science.

“A large part of why we are doing this is not to invent a photo detector, but to understand the processes involved in controlling carbon nanotube devices,” says Léonard.

The next step in the project is to create a nanometer-scale photovoltaic device. Such a device on a larger scale could be used as an unpowered photo detector or for solar energy. “Instead of monitoring current changes, we’d actually generate current,” says Vance. “We have an idea of how to do it, but it will be a more challenging fabrication process.”

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.

April 9, 2009

Nanogenerator/solar cell combo

This sounds like a very promising nanotechwith practical applications. I enjoy blogging on both nanotechnology and solar energy research, but it’s always more interesting when the breakthrough are somewhere close to actual real world application.

From the Technology Review link:

Nanoscale generators can turn ambient mechanical energy–vibrations, fluid flow, and even biological movement–into a power source. Now researchers have combined a nanogenerator with a solar cell to create an integrated mechanical- and solar-energy-harvesting device. This hybrid generator is the first of its kind and might be used, for instance, to power airplane sensors by capturing sunlight as well as engine vibrations.

Nanogenerators typically use piezoelectric nanowires–hairlike zinc oxide structures that generate an electrical potential when mechanically stressed–to produce small amounts of power. The first such devices were made by Zhong Lin Wang, a professor at Georgia Tech and director of the institute’s Center for Nanostructure Characterization. Wang hopes that nanogenerators will one day eliminate the need for batteries in implantable medical sensors, and will eventually generate enough power to charge up larger personal electronics.

Nano hybrid: A dye-sensitized solar cell (top) and a nanogenerator (bottom) sit on the same substrate in the new device. Credit: Xudong Wang

Nano hybrid: A dye-sensitized solar cell (top) and a nanogenerator (bottom) sit on the same substrate in the new device. Credit: Xudong Wang

January 23, 2009

Carbon nanotube electronics hit the market

Filed under: Business, Science, Technology — Tags: , , , , , — David Kirkpatrick @ 12:39 am

Very exciting news here. A transparent plastic product with a carbon nanotube coating will be the first electronic nanotube product to hit the market. Lots of promising applications with this product.

From the link:

The first electronic product using carbon nanotubes is slated to hit the market this year. Unidym, a startup based in Menlo Park, CA, plans to start selling rolls of its carbon-nanotube-coated plastic films in the second half of 2009.

The transparent, conductive films could make manufacturing LCD screens faster and cheaper. They could enhance the life of touch panels used in ATM screens and supermarket kiosks. They might also pave the way for flexible thin-film solar cells and bright, roll-up color displays. The displays could be used in cell phones, billboards, and electronic books and magazines.

In all of these applications, the nanotube sheets would replace the indium tin oxide (ITO) coatings that are currently used as transparent electrodes. ITO cracks easily and is a more expensive material. “The cost of indium has gone up by 100 times in the last 10 years,” says Peter Harrop, chairman of IDTechEx, a research and consulting firm based in Cambridge, U.K.


Nanotube shrink-wrap: A small sample of the carbon-nanotube-coated plastic film that could be used as the see-through electrodes in touch screens, roll-up displays, and thin-film solar cells. Credit: Unidym

December 10, 2008

Thin film solar cell market heading toward $5B by 2011

The release:

Revised NanoMarkets Numbers Show Thin Film Photovoltaic Cell Market at $4.6 Billion by 2011

GLEN ALLEN, Va., Dec. 10 /PRNewswire-FirstCall/ — NanoMarkets, a leading industry analyst firm based here, today announced it has released an updated analysis of the thin-film photovoltaics (TFPV) markets.  The firm projects that after a few lean years in 2009 and 2010 for the TFPV business higher growth rates will return in 2011.  The firm’s new analysis and forecast projects revenues of $4.6 billion in 2011 that will grow to just over $14 billion in 2015.  Additional details about the report are available at www.nanomarkets.net.

Key Insights:

According to NanoMarkets, several factors are combining to make the near-term prospects for TFPV less rosy than had once been hoped.  The global economic situation is having wide ranging impacts on the thin-film solar business.  The recession in the construction industry will dampen demand for solar panels in 2009 and 2010,  depressed oil prices will make it harder to make the case for solar and other forms of alternative energies and competition for capital will limit funding for R&D.  Furthermore, the shortage of crystalline silicon that was one of the initial drivers for TFPV has been resolved.  Add in the capacity that is coming on line to meet expected demand and the market certainly has factors to overcome.

Nonetheless, NanoMarkets does not believe that the thin-film solar business will evaporate.  The unique combination of flexibility, low weight and low cost promised by TFPV will enable the technology to continue to penetrate the solar market as a whole.   First Solar has already demonstrated how commercially successful its thin-film CdTe cell technology can be and NanoMarkets also expects to see a major ramp up in CIGS solar panels in the early 2011 timeframe.   Indeed, as CIGS begins to fulfill its mission of combining high efficiencies with all the advantages of TFPV, NanoMarkets expects firms that are now focused on other materials platforms to switch to CIGS.

About the Report:

NanoMarkets’ report, Thin Film Photovoltaics Markets: 2008 and Beyond (Revised Edition) quantifies the opportunities for PV based on amorphous and other forms of thin-film silicon, CdTe, CIS/CIGS, GaAs as well as novel thin-film materials such as nanomaterials.  Applications for TFPV discussed in this report include electric utilities, commercial and industrial buildings, residential buildings, and military and emergency applications.

Detailed volume and value forecasts are provided for each application.  In addition, the report includes possible high-end and low-end scenarios for TFPV markets. These scenarios enable the TFPV community to plan successfully for the highly uncertain future that they now face. We have also included revised discussions of influential suppliers of TFPV products taking into account announcements and developments since the original version of this report. This new analysis shows the latest thinking on TFPV product development and R&D.

About NanoMarkets:

NanoMarkets tracks and analyzes emerging market opportunities in electronics created by developments in advanced materials. The firm has published numerous reports related to organic, thin film and printable electronics materials and applications and maintains a blog at www.nanotopblog.com that comments on industry trends and events. NanoMarkets research database is the industry’s most extensive source of information on thin film, organic and printable (TOP) electronics. Visit www.nanomarkets.net for a full listing of NanoMarkets’ reports and other services.

Source: NanoMarkets
   Web site:  http://www.nanomarkets.net/

December 9, 2008

Giant frickin’ laser!

Filed under: Business, Science, Technology — Tags: , , , , , — David Kirkpatrick @ 12:35 pm

Okay, that was a flippant header for a serious press release. I couldn’t resist.

JDSU announces a high-powered laser that improves solar cell production. Pretty frickin’ cool.

The release:

JDSU Introduces New High Powered Ultra Violet Laser

Latest Q Series Laser Designed to Increase Manufacturing Productivity of OEMs for Precision Micromachining and Solar Cell Processing

MILPITAS, Calif., Dec. 9 /PRNewswire-FirstCall/ — JDSU (Nasdaq: JDSU; TSX: JDU) today announced availability of a new high power ultraviolet (UV) laser called the Q304-HD laser.  Based upon the widely adopted Q Series UV laser platform from JDSU, the new laser provides 50 percent more power and is designed to increase throughput, or the rate at which it can conduct micromachining functions such as hole drilling, wafer cutting or singulation, and solar cell processing. Higher throughput from the laser allows manufacturers to increase productivity during the manufacturing of products, saving valuable time and costs.

In addition, the new laser operates at a higher power level without using additional electrical consumption due to enhancements in the new laser design. This also ensures a longer laser lifespan.

“Manufacturers are under pressure to reduce costs while increasing productivity by adopting aggressive manufacturing processes,” said Victor David, product line manager for Q Series lasers in the Communications and Commercial Optical Products business segment at JDSU.  “We’ve received positive responses from customers about the new JDSU Q304-HD laser because it allows them to produce more products in less time. It also provides the same high reliability and precision as previous offerings based on the Q Series platform.”

  JDSU Q304-HD Laser Performance Advantages
  —  50 percent more power: >11W at 355 nanometers.
  —  Longer laser lifespan.
  —  Best-in-class beam quality at M2 <1.2.
  —  Unmatched pulse energy stability for repeatability.
  —  Near instantaneous power control.
  —  Superior process control and flexibility for a wide range materials
      and machine integration conditions.

  About JDSU

JDSU (NASDAQ: JDSU; and TSX: JDU) enables broadband and optical innovation in the communications, commercial and consumer markets. JDSU is the leading provider of communications test and measurement solutions and optical products for telecommunications service providers, cable operators, and network equipment manufacturers. JDSU is also a leading provider of innovative optical solutions for medical/environmental instrumentation, semiconductor processing, display, brand authentication, aerospace and defense, and decorative applications. More information is available at http://www.jdsu.com/.

 Photo:  NewsCom: http://www.newscom.com/cgi-bin/prnh/20050913/SFTU125LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk, photodesk@prnewswire.com
Source: JDSU
Web site:  http://www.jdsu.com/

November 18, 2008

Research to improve solar cells

Basic research of this nature is the heart and soul of science and eventually technological breakthroughs.

The release:

Precise measurement of phenomenon advances solar cell understanding

Moving down the chain

By Melissae Stuart

Nov. 18, 2008 — Researchers at Washington University in St. Louis have shed light on a basic process that could improve future solar cells.

“One type of solar cell design starts with a chain of chromophores strung between two electrodes,” explained Dewey Holten, Ph.D., professor of chemistry in Arts & Sciences. “This chain absorbs the light energy and directs that energy toward one electrode, where it is deposited as an electron. The molecule that lost the electron now has a positive charge left behind, called a hole. The hole migrates down the chain toward the opposite electrode. The electron and the hole recombine in the external circuit, creating an electrical current to do work.”

Dewey Holten, Ph.D., WUSTL professor of chemistry in Arts & Sciences (left) and WUSTL chemistry graduate student Hee-eun Song examine data in Holten’s laboratory. The two have made a breakthrough in the electron transfer process that could have a significant impact on solar cell design.

Holten and graduate student Hee-eun Song have directly measured the rate of hole transfer between identical porphyrin compounds in their ground states. These results are key to understanding the fundamental processes underlying charge separation in this sort of structure and have applications for improving the efficiency of solar cells.

Their results represent the first time that ground-state hole transfer rates have been precisely measured. Previously, hole transfer in chains of porphrin molecules was known to take from 20 picoseconds to 50 nanoseconds, a range that spans three orders of magnitude. These studies have defined the time as 0.5-1 nanosecond.

The work has been published in the Journal of the American Chemical Society and is in press at the Journal of Physical Chemistry B and Photochemistry and Photobiology. The Department of Energy Solar Photochemistry Program provided funding.

Hopping downhill

Thermodynamic stability is often the driving force for the hole to move down the chain. However, this requires that the chain be made up of a variety of molecules so that each hop is downhill in energy.

“From a synthetic standpoint, it is easier to build a string of similar molecules with a minimum number of energy gradient steps built in. The challenge then becomes monitoring hole transfer between identical molecules,” said Holten.

The multiporphyrinic arrays they studied were synthesized by a group at North Carolina State University under the direction of Jonathan Lindsey, Ph.D., Glaxo Distinguished University Professor of Chemistry.

Holten and his group placed the molecular arrays in a predefined starting form by electrochemically oxidizing one of the porphyrins to generate the hole and exciting another with light to make an electronic excited state. Then they used ultrafast femtosecond timescale transient absorption spectroscopy to monitor the hole transfer process between equivalent porphyrins.

“We compared the spectroscopic and kinetic results for the monomer, dyads, and triads,” Holten said. “From this information, we could back out the rates of hole transfer between the equivalent sites.”

David Bocian, Ph.D., professor of chemistry at the University of California, Riverside and his group performed additional spectroscopic studies.

“This work is an example of how an exciting collaboration between scientists can produce results that are fundamentally important, develop a general experimental method that can be adopted by other scientists, and also have real world applications,” said Holten.


October 23, 2008

Solar cell with 25% efficiency

Solar keeps improving by leaps and bounds these days. Encouraging news from the University of New South Wales.

The release:

Magic solar milestone reached

UNSW claims 25 percent solar cell efficiency title

UNSW’s ARC Photovoltaic Centre of Excellence has again asserted its leadership in solar cell technology by reporting the first silicon solar cell to achieve the milestone of 25 per cent effiency.

The UNSW ARC Photovoltaic Centre of Excellence already held the world record of 24.7 per cent for silicon solar cell efficiency. Now a revision of the international standard by which solar cells are measured, has delivered the significant 25 per cent record to the team led by Professors Martin Green and Stuart Wenham and widened their lead on the rest of the world.

Centre Executive Research Director, Scientia Professor Martin Green, said the new world mark in converting incident sunlight into electricity was one of six new world records claimed by UNSW for its silicon solar technologies.

Professor Green said the jump in performance leading to the milestone resulted from new knowledge about the composition of sunlight.

“Since the weights of the colours in sunlight change during the day, solar cells are measured under a standard colour spectrum defined under typical operational meteorological conditions,” he said.

“Improvements in understanding atmospheric effects upon the colour content of sunlight led to a revision of the standard spectrum in April. The new spectrum has a higher energy content both down the blue end of the spectrum and at the opposite red end with, dare I say it, relatively less green.”

The recalibration of the international standard, done by the International Electrochemical Commission in April, gave the biggest boost to UNSW technology while the measured efficiency of others made lesser gains. UNSW’s world-leading silicon cell is now six per cent more efficient than the next-best technology, Professor Green said. The new record also inches the UNSW team closer to the 29 per cent theoretical maximum efficiency possible for first-generation silicon photovoltaic cells.

Dr Anita Ho-Baillie, who heads the Centre’s high efficiency cell research effort, said the UNSW technology benefited greatly from the new spectrum “because our cells push the boundaries of response into the extremities of the spectrum”.

“Blue light is absorbed strongly, very close to the cell surface where we go to great pains to make sure it is not wasted. Just the opposite, the red light is only weakly absorbed and we have to use special design features to trap it into the cell,” she said.

Professor Green said: “These light-trapping features make our cells act as if they were much thicker than they are. This already has had an important spin-off in allowing us to work with CSG Solar to develop commercial ‘thin-film’ silicon-on-glass solar cells that are over 100 times thinner than conventional silicon cells.”

ARC Centre Director, Professor Stuart Wenham said the focus of the Centre is now improving mainstream production. “Our main efforts now are focussed on getting these efficiency improvements into commercial production,” he said. “Production compatible versions of our high efficiency technology are being introduced into production as we speak.”

The world-record holding cell was fabricated by former Centre researchers, Dr Jianhua Zhao and Dr Aihua Wang, who have since left the Centre to establish China Sunergy, one of the world’s largest photovoltaic manufacturers. “China was the largest manufacturer of solar cells internationally in 2007 with 70 per cent of the output from companies with our former UNSW students either Chief Executive Officers or Chief Technical Officers”, said Professor Green.



September 18, 2008

Solar cell manufacturers in Taiwan see almost 70% increase in revenue

The press release hit my inbox this morning:

Taiwan Solar Cell Revenues Soar in First Half of 2008

Revenues Jump 69.6 Percent From Same Period in 2007 on Strong Demand From Europe and Increases in Average Selling Prices

TAIPEI, Taiwan and SAN FRANCISCO, Sept. 18 /PRNewswire/ — Taiwan’s manufacturers of solar cells used to generate electricity reported revenues in the first half of 2008 that soared by 69.6 percent from the same period a year ago on strong demand from European nations such as Spain and Germany.

Six of the solar cell makers listed on Taiwan’s stock exchange reported first half 2008 revenues of NT$35.6 billion (US$1.1 billion) compared with NT$21 billion in the same period a year ago, based on information the companies provided to the stock exchange authorities.

The companies are Motech Industrial Inc., Gintech Energy Corp., E-Ton Solar Tech, Sino-American Silicon Products Inc., Sinonar Corp. and Green Energy Technology. Motech, Gintech and E-Ton are among the world’s ten largest solar cell makers by revenues.

Demand for solar cells and other sources of alternative energy has taken off after prices of oil soared the past 12 months.  Governments in Europe and Japan have subsidized the installation of solar energy facilities.  Demand for solar cells in the first half of this year has helped to boost average selling prices (ASPs), according to analysts who cover the companies.

“There has been an increase in ASPs due to supply constraints and strong demand from Spain,” said Daiwa Securities analyst Pranab Kumar Sarmah.  “There has also been a strong output ramp for a few new entrants such as Gintech.”

Sarmah expects the next U.S. president to decide on a new Federal Income Tax Credit (ITC) for solar systems, which expires at the end of this year. Residential users may delay purchases until the new ITC is in place, and pent-up demand has the potential to explode from the second half of 2009, assuming the new president provides similar or better federal incentives, he adds.

Still, demand may slow during the rest of this year if some European nations cut subsidies, analysts say.

“While many seem to recognize the potential market impact from the reduced subsidy in Spain, industry players are still optimistic on the long-term growth prospects, which we agree with,” says Citigroup Global Markets analyst George Chang.

This year, the solar cell manufacturers have been the best performing segment in Taiwan’s high technology industry, which includes companies making everything from semiconductors, flat-panel displays, computers, mobile phones and digital music players, analysts say.

The strong outlook for the industry is attracting more investment and manufacturers in Taiwan’s solar cell business.

Green Energy Technology, which makes silicon wafers that are used as a basic material in solar cells, announced on Sept. 1 it won annual orders worth of euro39.86 million (US$58.77 million) to supply thin-film solar modules to Germany and Spain next year.  The company has been cooperating with Applied Materials of the U.S. to develop a new 8.5 generation thin-film solar production line in Taoyuan that can produce large 2.2m x 2.6m thin-film modules with a power output of 343W per unit.

Applied Materials is the world’s largest supplier of equipment used to make semiconductors, flat-panel displays and solar cells.  The company in July broke ground for expansion of its Taiwan Manufacturing Center to meet demand for flat-panel display and solar cell manufacturing equipment.  The company estimated the investment to be worth about US$17 million.

Taiwan Glass Industrial Corp. said earlier this year that starting in August, it would invest US$11.9 million to start production of special glass used in the production of solar cells.  By 2012, the value of Taiwan’s solar industry production may reach NT$500 billion as the government promotes the use of sources of energy alternatives besides oil, according to Taiwan Premier Liu Chao-shiuan.

Taiwan should endeavor to develop green environmentally friendly industries and high value-added knowledge-intensive industries, the Taiwan Environmental Protection Administration said in a statement on its website. The government has helped to fund investments in solar cell research and technology as it aims for foster development of this new industry.

  Motech Industrial Inc.

  Gintech Energy Corp.

  E-Ton Solar Tech

  Sino-American Silicon Products Inc.

  Sinonar Corp.

  Green Energy Technology

Please visit http://www.taiwantrade.org.tw/ or http://www.brandingtaiwan.org/ for more information.

Taiwan External Trade Development Council (TAITRA)

The Taiwan External Trade Development Council (TAITRA) was founded in 1970 to promote Taiwan’s foreign trade and competitiveness in world markets. Over the past 38 years, TAITRA has played a key role in the development of the Taiwan economy. TAITRA is jointly sponsored by the government and commercial associations and is viewed by all as the business gateway to Taiwan for the international business community.

Source: Taiwan External Trade Development Council

Web site: http://www.taiwantrade.org.tw/

September 5, 2008

Improving solar through stronger sunlight

Concentrating sunlight gets solar more close to competing with fossil fuels. Solar breakthroughs are really hitting the wire on a regular basis these days.

From the Technology Review link:

In his darkened lab at MIT, Marc Baldo shines an ultraviolet lamp on a 10-­centimeter square of glass. He has coated the surfaces of the glass with dyes that glow faintly orange under the light. Yet the uncoated edges of the glass are shining more brightly–four neat, thin strips of luminescent orange.

The sheet of glass is a new kind of solar concentrator, a device that gathers diffuse light and focuses it onto a relatively small solar cell. Solar cells, multilayered electronic devices made of highly refined silicon, are expensive to manufacture, and the bigger they are, the more they cost. Solar concentrators can lower the overall cost of solar power by making it possible to use much smaller cells. But the concentrators are typically made of curved mirrors or lenses, which are bulky and require costly mechanical systems that help them track the sun.

Unlike the mirrors and lenses in conventional solar concentrators, Baldo’s glass sheets act as waveguides, channeling light in the same way that fiber-optic cables transmit optical signals over long distances. The dyes coating the surfaces of the glass absorb sunlight; different dyes can be used to absorb different wavelengths of light. Then the dyes reëmit the light into the glass, which channels it to the edges. Solar-cell strips attached to the edges absorb the light and generate electricity. The larger the surface of the glass compared with the thickness of the edges, the more the light is concentrated and, to a point, the less the power costs.

June 23, 2008

A couple of solar breaktroughs

From KurzweilAI.net — MIT students create a low-cost, low-tech solar dish, and carbon nanotubes may lower the cost and improve the performance of solar cells.

MIT team plays with fire to create cheap energy
Christian Science Monitor, June 18, 2008

A simple new low-cost solar dish developed by MIT students produces steam heat for less than the cost of heat from oil or natural gas, according to the MIT team.

The steam heat can be used cost effectively for manufacturing, food pasteurization, and heating buildings.
Read Original Article>>


Perfecting a solar cell by adding imperfections
PhysOrg.com, June 16, 2008

New research at Santa Fe Institute, Michigan State University, and Columbia University shows that a film of carbon nanotubes may be able to replace two of the layers normally used in a solar cell, with improved performance at lower cost.

Exposing the carbon nanotubes to ozone made the carbon nanotubes better catalysts, with more than a ten-fold improvement, and replaced expensive platinum. And making them longer improved both conductivity and transparency.

The carbonnanotube films might also be used in fuel cells and batteries.

Read Original Article>>