(Press-News.org) Dye-sensitized solar cells (DSSCs) have many advantages over their silicon-based counterparts. They offer transparency, low cost, and high power conversion efficiencies under cloudy and artificial light conditions. However, until now their overall efficiency has been lower than silicon-based solar cells, mostly because of the inherent voltage loss during the regeneration of the sensitizing dye. In a Nature publication, EPFL scientists have developed a state solid version of the DSSC that is fabricated by a new two-step process raising their efficiency up to a record 15% without sacrificing stability.
The new solid-state embodiment of the DSSC uses a perovskite (CaTiO3) material as a light harvester and an organic hole transport material to replace the cell's electrolyte. Typical fabrication of this new DSSC involves depositing a perovskite material directly onto a metal-oxide film. The problem is that adding the entire material together often causes wide variation in the morphology and the efficiency of the resulting solar cell, which makes it difficult to use them in everyday applications.
Michael Grätzel's team at EPFL has now solved the problem with a two-step approach: First, one part of the perovskite is deposited in to the pores of the metal-oxide scaffold. Second, the deposited part is exposed to a solution that contains the other component of the perovskite. When the two parts come into contact, they react instantaneously and convert into the complete light-sensitive pigment, permitting much better control over the morphology of the solar cell.
The new method raises DSSC power-conversion efficiency up to a record 15%, exceeding the power conversion efficiencies of conventional, amorphous silicon-based solar cells. The authors believe that it will open a new era of DSSC development, featuring stability and efficiencies that equal or even surpass today's best thin-film photovoltaic devices.
INFORMATION:
Dye-sensitized solar cells rival conventional cell efficiency
2013-07-11
ELSE PRESS RELEASES FROM THIS DATE:
Size matters for creatures of cold polar waters
2013-07-11
Scientists at the Universities of Liverpool, Plymouth, and Radboud, Netherlands, have challenged the view that giant animals are found in polar seas because of a superabundance of oxygen in cold water.
It is thought that giant insects and other creatures hundreds of millions of years ago evolved due to a superabundance of oxygen and that this could also explain the existence of giant sea creatures today. The new research, published in Functional Ecology, however, suggests that this may not be the case.
The research suggests that large animals survive in polar oceans ...
New virus discovered in stranded dolphin
2013-07-11
Researchers at the Center for Infection and Immunity at Columbia University's Mailman School of Public Health and colleagues have identified a new virus associated with the death of a short-beaked dolphin found stranded on a beach in San Diego. It is the first time that a virus belonging to the polyomavirus family has been found in a dolphin. Results appear online in the journal PLOS ONE.
Polyomavirus is known to cause disease in birds, but in mammals it is usually mild or subclinical, explains lead author Simon Anthony, PhD, a researcher in the Center for Infection and ...
IU researchers create the inner ear from stem cells, opening potential for new treatments
2013-07-11
INDIANAPOLIS -- Indiana University scientists have transformed mouse embryonic stem cells into key structures of the inner ear. The discovery provides new insights into the sensory organ's developmental process and sets the stage for laboratory models of disease, drug discovery and potential treatments for hearing loss and balance disorders.
A research team led by Eri Hashino, Ph.D., Ruth C. Holton Professor of Otolaryngology at Indiana University School of Medicine, reported that by using a three-dimensional cell culture method, they were able to coax stem cells to develop ...
Study confirms link between omega-3 fatty acids and increased prostate cancer risk
2013-07-11
SEATTLE – A second large, prospective study by scientists at Fred Hutchinson Cancer Research Center has confirmed the link between high blood concentrations of omega-3 fatty acids and an increased risk of prostate cancer.
Published July 11 in the online edition of the Journal of the National Cancer Institute, the latest findings indicate that high concentrations of EPA, DPA and DHA – the three anti-inflammatory and metabolically related fatty acids derived from fatty fish and fish-oil supplements – are associated with a 71 percent increased risk of high-grade prostate ...
Dinosaurs, diets and ecological niches: Study shows recipe for success
2013-07-11
OTTAWA, July 10, 2013—A new study by a Canadian Museum of Nature scientist helps answer a long-standing question in palaeontology—how numerous species of large, plant-eating dinosaurs could co-exist successfully over geological time.
Dr. Jordan Mallon, a post-doctoral fellow at the museum, tackled the question by measuring and analyzing characteristics of nearly 100 dinosaur skulls recovered from the Dinosaur Park Formation in Alberta, Canada. The specimens now reside in major fossil collections across the world, including that of the Canadian Museum of Nature. The work ...
Intestinal bacteria may fuel inflammation and worsen HIV disease
2013-07-11
A new study of HIV infection by UC San Francisco researchers points to changes in intestinal bacteria as a possible explanation for why successfully treated HIV patients nonetheless prematurely experience life-shortening chronic diseases.
These changes in gut bacteria may perpetuate inflammation initially triggered by the body's immune response to HIV, according to the study, reported online July 10 in the journal Science Translational Medicine.
In recent years, such persistent inflammation has been proposed as a cause of the early onset of common chronic diseases found ...
Combination of smoking and heavy drinking 'speeds up cognitive decline'
2013-07-11
The combination of smoking and heavy drinking speeds up cognitive decline, according to new research published in the British Journal of Psychiatry.
Researchers from UCL (University College London) found that smokers who drank alcohol heavily had a 36% faster cognitive decline compared to non-smoking moderate drinkers.
Smoking and heavier alcohol consumption often co-occur, and their combined effect on cognition may be larger than the sum of their individual effects. The research team assessed 6,473 adults (4,635 men and 1,838 women) aged between 45 and 69 years old ...
Prisoners doing yoga may see psychological benefits
2013-07-11
Yoga can improve mood and mental wellbeing among prisoners, an Oxford University study suggests, and may also have an effect on impulsive behaviour.
The researchers found that prisoners after a ten-week yoga course reported improved mood, reduced stress and were better at a task related to behaviour control than those who continued in their normal prison routine.
'We found that the group that did the yoga course showed an improvement in positive mood, a decrease in stress and greater accuracy in a computer test of impulsivity and attention,' say Dr Amy Bilderbeck and ...
A new way to trap light
2013-07-11
CAMBRIDGE, MA -- There are several ways to "trap" a beam of light — usually with mirrors, other reflective surfaces, or high-tech materials such as photonic crystals. But now researchers at MIT have discovered a new method to trap light that could find a wide variety of applications.
The new system, devised through computer modeling and then demonstrated experimentally, pits light waves against light waves: It sets up two waves that have the same wavelength, but exactly opposite phases — where one wave has a peak, the other has a trough — so that the waves cancel each ...
Trees using water more efficiently as atmospheric carbon dioxide rises
2013-07-11
DURHAM, N.H., July 10, 2013 – A study by scientists with the U.S. Forest Service, Harvard University and partners suggests that trees are responding to higher atmospheric carbon dioxide levels by becoming more efficient at using water.
The study, "Increase in forest water-use efficiency as atmospheric carbon dioxide concentrations rise," was published on-line today in the journal Nature. Dave Hollinger, a plant physiologist with the U.S. Forest Service's Northern Research Station, is a co-author with lead author Trevor Keenan of Harvard University and colleagues from ...