FROM: LOS ALAMOS NATIONAL LABORATORY
Nontoxic Quantum Dot Research Improves Solar Cells
Record power-conversion efficiency at Los Alamos from quantum-dot sensitized photovoltaics
LOS ALAMOS, N.M., Dec. 10, 2013—Solar cells made with low-cost, non-toxic copper-based quantum dots can achieve unprecedented longevity and efficiency, according to a study by Los Alamos National Laboratory and Sharp Corporation.
“For the first time, we have certified the performance of a quantum dot sensitized solar cell at greater than 5 percent, which is among the highest reported for any quantum dot solar cell,” said Hunter McDaniel, a Los Alamos postdoctoral researcher and the lead author on a paper appearing in Nature Communications this week. “The robust nature of these devices opens up the possibility for commercialization of this emerging low-cost and low-toxicity photovoltaic technology,” he noted.
The reported solar cells are based on a new generation of nontoxic quantum dots (not containing either lead or cadmium as do most quantum dots used in solar cells). These dots are based on copper indium selenide sulfide and are rigorously optimized to reduce charge-carrier losses from surface defects and to provide the most complete coverage of the solar spectrum.
“The new solar cells were certified by the National Renewable Energy Laboratory (NREL) and demonstrated a record power-conversion efficiency for this type of devices,” according to Victor Klimov of Los Alamos, director of the Center for Advanced Solar Photophysics a DOE Energy Frontier Research Centers (EFRC). In addition to CASP-EFRC, this research has been also supported via a cooperative research agreement with Sharp Corporation.
The paper, “An integrated approach to realizing high-performance liquid-junction quantum dot sensitized solar cells” is scheduled for online publication in Nature Communications on Dec. 10, 2013.
The paper's authors are Hunter McDaniel, Nikolay S. Makarov, Jeffrey M. Pietryga, and Victor I. Klimov of the Center for Advanced Solar Photophysics, Los Alamos National Laboratory, in partnership with Nobuhiro Fuke of the Materials & Energy Technology Laboratory, Sharp Corporation, Japan.
Showing posts with label SOLAR SPECTRUM. Show all posts
Showing posts with label SOLAR SPECTRUM. Show all posts
Thursday, December 12, 2013
Sunday, November 10, 2013
NANOGRID TECHNOLOGY MAY BE USEFUL IN BREAKING DOWN WATER POLLUTANTS
FROM: NATIONAL SCIENCE FOUNDATION
Nanogrid, activated by sunlight, breaks down pollutants in water, leaving biodegradable compounds
November 8, 2013
Oil spills do untold damage to the environment--to the waters they pollute and to marine and other wildlife. The Deepwater Horizon spill in the Gulf of Mexico in 2010, for example, the largest accidental marine oil spill in the history of the petroleum industry, flowed unabated for three months.
Typically, such oil spills are extraordinarily difficult to clean up.
Soon, however, the process may become infinitely easier and ecologically friendly, the result of a new invention by a National Science Foundation- (NSF) supported scientist.
Pelagia-Irene (Perena) Gouma, a professor in the Department of Materials Science and Engineering at the State University of New York (SUNY) Stony Brook, created a novel "nanogrid," a large net consisting of metal grids made of a copper tungsten oxide, that, when activated by sunlight, can break down oil from a spill, leaving only biodegradable compounds behind.
"We have made a new catalyst that can break down hydrocarbons in water, and it does not contaminate the water," says Gouma, who also directs SUNY's Center for Nanomaterials and Sensor Development. "It utilizes the whole solar spectrum and can work in water for a long time, which no existing photocatalyst can do now. Ours is a unique technology. When you shine light on these grids, they begin to work and can be used over and over again.
"Something like this would work fine for any oil spill," Gouma adds. "Any ship can carry them, so if they have even a small amount of spill, they can take care of it."
Initially, the grids, which resemble non-woven mats of miniaturized ceramic fishing nets, probably will be used for oil spills, although they potentially could prove valuable in other applications, such as cleaning contaminated water produced by "fracking," the process of hydraulic fracturing to extract natural gas from shale, and as well as from other industrial processes.
"Fracking is a reality," she says. "It is happening. If the science and engineering we produce in the lab can help alleviate environmental problems, we will be happy about that."
Because they work well both in water and air, they also could be a chemical-free, possibly even water-free, method of cleaning clothes in the future. "The dry cleaning process that we now use involves a lot of contaminants that have to be remediated and treated, such as benzene," she says. "This could be a dry cleaning substitute that would be more environmentally friendly than current dry cleaning approaches."
Moreover, "imagine you lay this over your clothes, and expose them to light. You won't need a washing machine, or chemicals, or even water," she adds.
The photocatalytic nanogrids™ invented in her lab are made by a unique self-assembly process that occurs "during the nanomanufacturing on non-woven nanofibrous mats deposited on metal meshes," according to Gouma. "Upon heating, metal clusters diffuse inside polymeric nanofibers, then turn into single crystal nanowires, then oxidize to form metal oxide--ceramic--nanoparticles that are interconnected, like links in a chain," she says.
These form an unusual and "robust third architecture that allows for the highest surface area, providing maximum exposure to the contaminant to be remediated, while the nanoscale particle sizes enable fast catalytic action," she adds. "The result is a self-supported water remediation targeted photocatalytic technology that has no precedent."
In the fall of 2011, Gouma was the first scientist to receive a $50,000 NSF Innovation Corps (I-Corps) award, which supports a set of activities and programs that prepare scientists and engineers to extend their focus beyond the laboratory into the commercial world.
Such results may be translated through I-Corps into technologies with near-term benefits for the economy and society. It is a public-private partnership program that teaches grantees to identify valuable product opportunities that can emerge from academic research, and offers entrepreneurship training to faculty and student participants.
"The I-Corps program was very useful for the students," she says. "It got them involved, and got them to realize that there is a practical application to what they do. It was extremely useful for them to see how something developed in the lab could be used in the field, and that you actually can start a business from something started in the lab."
She and her team are in the process of creating a startup business--they have two patents pending on the process--with the hope of scaling up production and carrying out pilot studies.
"We want to demonstrate feasibility in the real world, and then produce them in large quantities," she says. "We have proof of principle that our technology can be useful. Our technique works in the lab. We now need to make sure that it works in the field."
-- Marlene Cimons, National Science Foundation
Investigators
Jusang Lee
Clive Clayton
Pelagia Gouma
Nanogrid, activated by sunlight, breaks down pollutants in water, leaving biodegradable compounds
November 8, 2013
Oil spills do untold damage to the environment--to the waters they pollute and to marine and other wildlife. The Deepwater Horizon spill in the Gulf of Mexico in 2010, for example, the largest accidental marine oil spill in the history of the petroleum industry, flowed unabated for three months.
Typically, such oil spills are extraordinarily difficult to clean up.
Soon, however, the process may become infinitely easier and ecologically friendly, the result of a new invention by a National Science Foundation- (NSF) supported scientist.
Pelagia-Irene (Perena) Gouma, a professor in the Department of Materials Science and Engineering at the State University of New York (SUNY) Stony Brook, created a novel "nanogrid," a large net consisting of metal grids made of a copper tungsten oxide, that, when activated by sunlight, can break down oil from a spill, leaving only biodegradable compounds behind.
"We have made a new catalyst that can break down hydrocarbons in water, and it does not contaminate the water," says Gouma, who also directs SUNY's Center for Nanomaterials and Sensor Development. "It utilizes the whole solar spectrum and can work in water for a long time, which no existing photocatalyst can do now. Ours is a unique technology. When you shine light on these grids, they begin to work and can be used over and over again.
"Something like this would work fine for any oil spill," Gouma adds. "Any ship can carry them, so if they have even a small amount of spill, they can take care of it."
Initially, the grids, which resemble non-woven mats of miniaturized ceramic fishing nets, probably will be used for oil spills, although they potentially could prove valuable in other applications, such as cleaning contaminated water produced by "fracking," the process of hydraulic fracturing to extract natural gas from shale, and as well as from other industrial processes.
"Fracking is a reality," she says. "It is happening. If the science and engineering we produce in the lab can help alleviate environmental problems, we will be happy about that."
Because they work well both in water and air, they also could be a chemical-free, possibly even water-free, method of cleaning clothes in the future. "The dry cleaning process that we now use involves a lot of contaminants that have to be remediated and treated, such as benzene," she says. "This could be a dry cleaning substitute that would be more environmentally friendly than current dry cleaning approaches."
Moreover, "imagine you lay this over your clothes, and expose them to light. You won't need a washing machine, or chemicals, or even water," she adds.
The photocatalytic nanogrids™ invented in her lab are made by a unique self-assembly process that occurs "during the nanomanufacturing on non-woven nanofibrous mats deposited on metal meshes," according to Gouma. "Upon heating, metal clusters diffuse inside polymeric nanofibers, then turn into single crystal nanowires, then oxidize to form metal oxide--ceramic--nanoparticles that are interconnected, like links in a chain," she says.
These form an unusual and "robust third architecture that allows for the highest surface area, providing maximum exposure to the contaminant to be remediated, while the nanoscale particle sizes enable fast catalytic action," she adds. "The result is a self-supported water remediation targeted photocatalytic technology that has no precedent."
In the fall of 2011, Gouma was the first scientist to receive a $50,000 NSF Innovation Corps (I-Corps) award, which supports a set of activities and programs that prepare scientists and engineers to extend their focus beyond the laboratory into the commercial world.
Such results may be translated through I-Corps into technologies with near-term benefits for the economy and society. It is a public-private partnership program that teaches grantees to identify valuable product opportunities that can emerge from academic research, and offers entrepreneurship training to faculty and student participants.
"The I-Corps program was very useful for the students," she says. "It got them involved, and got them to realize that there is a practical application to what they do. It was extremely useful for them to see how something developed in the lab could be used in the field, and that you actually can start a business from something started in the lab."
She and her team are in the process of creating a startup business--they have two patents pending on the process--with the hope of scaling up production and carrying out pilot studies.
"We want to demonstrate feasibility in the real world, and then produce them in large quantities," she says. "We have proof of principle that our technology can be useful. Our technique works in the lab. We now need to make sure that it works in the field."
-- Marlene Cimons, National Science Foundation
Investigators
Jusang Lee
Clive Clayton
Pelagia Gouma
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