PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

New kind of 'tandem' solar cell developed

Researchers combine 2 types of photovoltaic material to make a cell that harnesses more sunlight

2015-03-24
(Press-News.org) CAMBRIDGE, Mass--Researchers at MIT and Stanford University have developed a new kind of solar cell that combines two different layers of sunlight-absorbing material in order to harvest a broader range of the sun's energy. The development could lead to photovoltaic cells that are more efficient than those currently used in solar-power installations, the researchers say.

The new cell uses a layer of silicon -- which forms the basis for most of today's solar panels -- but adds a semi-transparent layer of a material called perovskite, which can absorb higher-energy particles of light. Unlike an earlier "tandem" solar cell reported by members of the same team earlier this year -- in which the two layers were physically stacked, but each had its own separate electrical connections -- the new version has both layers connected together as a single device that needs only one control circuit.

The new findings are reported in the journal Applied Physics Letters by MIT graduate student Jonathan Mailoa; associate professor of mechanical engineering Tonio Buonassisi; Colin Bailie and Michael McGehee at Stanford; and four others.

"Different layers absorb different portions of the sunlight," Mailoa explains. In the earlier tandem solar cell, the two layers of photovoltaic material could be operated independently of each other and required their own wiring and control circuits, allowing each cell to be tuned independently for optimal performance.

By contrast, the new combined version should be much simpler to make and install, Mailoa says. "It has advantages in terms of simplicity, because it looks and operates just like a single silicon cell," he says, with only a single electrical control circuit needed.

One tradeoff is that the current produced is limited by the capacity of the lesser of the two layers. Electrical current, Buonassisi explains, can be thought of as analogous to the volume of water passing through a pipe, which is limited by the diameter of the pipe: If you connect two lengths of pipe of different diameters, one after the other, "the amount of water is limited by the narrowest pipe," he says. Combining two solar cell layers in series has the same limiting effect on current.

To address that limitation, the team aims to match the current output of the two layers as precisely as possible. In this proof-of-concept solar cell, this means the total power output is about the same as that of conventional solar cells; the team is now working to optimize that output.

Perovskites have been studied for potential electronic uses including solar cells, but this is the first time they have been successfully paired with silicon cells in this configuration, a feat that posed numerous technical challenges. Now the team is focusing on increasing the power efficiency -- the percentage of sunlight's energy that gets converted to electricity -- that is possible from the combined cell. In this initial version, the efficiency is 13.7 percent, but the researchers say they have identified low-cost ways of improving this to about 30 percent -- a substantial improvement over today's commercial silicon-based solar cells -- and they say this technology could ultimately achieve a power efficiency of more than 35 percent.

They will also explore how to easily manufacture the new type of device, but Buonassisi says that should be relatively straightforward, since the materials lend themselves to being made through methods very similar to conventional silicon-cell manufacturing.

One hurdle is making the material durable enough to be commercially viable: The perovskite material degrades quickly in open air, so it either needs to be modified to improve its inherent durability or encapsulated to prevent exposure to air -- without adding significantly to manufacturing costs and without degrading performance.

This exact formulation may not turn out to be the most advantageous for better solar cells, Buonassisi says, but is one of several pathways worth exploring. "Our job at this point is to provide options to the world," he says. "The market will select among them."

INFORMATION:

The research team also included Eric Johlin PhD '14 and postdoc Austin Akey at MIT, and Eric Hoke and William Nguyen of Stanford. It was supported by the Bay Area Photovoltaic Consortium and the U.S. Department of Energy.



ELSE PRESS RELEASES FROM THIS DATE:

What is the definition of 'natural' foods? Consumers want to know

2015-03-24
After decades of debate there remains no generally accepted definition of a "natural" food product. Regulatory agencies have refused to settle the issue but may be under new pressure from consumer lawsuits, according to a new study in the Journal of Public Policy & Marketing. "Consumers don't agree on a definition either, yet clearly believe that 'natural' is important," writes author Ross D. Petty (Babson College). "In 2009, 30% of newly launched foods claimed to be natural but by 2013 this dropped to 22%, possibly due to an increase in the number of consumer lawsuits. ...

Diabetics with ankle fractures have longer lengths of stay, more health care costs

2015-03-24
New research from NYU Langone orthopaedic surgeons finds patients with diabetes who fracture their ankle incur significantly more inpatient health care costs compared to patients who do not have diabetes. The research, led by Kenneth A. Egol, MD, a professor and vice chair of education in the Department of Orthoapedic Surgery at NYU Langone, showed patients with diabetes who undergo ankle fracture surgery have significantly longer lengths of stay and total hospital charges compared to non-diabetics, with worse trends seen among patients with complicated disease. NYU ...

New study indicates laparoscopic hysterectomy with morcellation may be safer than abdominal procedure

2015-03-24
Philadelphia, PA, March 24, 2015 - In a new study published in the American Journal of Obstetrics & Gynecology, researchers from The University of North Carolina at Chapel Hill compared the relative risks of laparoscopic hysterectomy (with morcellation) with abdominal surgery for hysterectomy in premenopausal women undergoing surgery for presumed uterine fibroids. Examining short- and long-term complications, quality of life, and overall mortality, they found that abdominal surgery carries a higher risk of complications, decreased quality of life, and death. Hysterectomy ...

Higher volume of scoliosis surgeries linked to reduced reoperation rates

2015-03-24
Adolescent patients who need scoliosis surgery may benefit most from going to a hospital that performs a high volume of the procedures, according to new research from NYU Langone spine surgeons presented March 24 at the American Academy of Orthopaedic Surgeons 2015 Annual Meeting in Las Vegas. Researchers looked at a New York State database of hospital discharges and identified 3,928 surgeries for adolescent idiopathic scoliosis, and found reoperation rates were significantly lower among surgeons who perform a high volume of the procedures. Specifically, 14.1 percent ...

NIH researchers identify red blood cell traits associated with malaria risk in children

2015-03-24
WHAT: Researchers at the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, have determined that certain red blood cell traits in children can increase or decrease their risk for malaria. The findings could help identify future targets for new malaria drugs and vaccines. From 2008 to 2011, NIAID scientists and their collaborators followed 1,543 children ranging from 6 months to 17 years old in Mali, a West African country with a high incidence of childhood malaria. Throughout the study period, the children experienced a ...

Preparing for natural disasters: What policies protect the vulnerable consumer?

2015-03-24
Despite catastrophic earthquakes, the most vulnerable residents do not take steps to prepare themselves against future disaster, according to a new study in the Journal of Public Policy & Marketing. The authors provide an example from southern Spain. "Spain's persistent economic crisis and unemployment rate suggest that many residents of southern Spain belong to this vulnerable segment," write authors Shintaro Okazaki (Universidad Autónoma de Madrid), Amadeo Benavent-Climent (University of Madrid), Angeles Navarro (Universidad de Murcia), and Jörg Henseler (University ...

Use your real name: Online communication details that affect sales

2015-03-24
Online word-of-mouth communications are having a significant effect on product sales, yet research to date has failed to understand why that effect fluctuates, according to a new study in the Journal of Marketing. "Previous investigation into online communications had focused on product reviews, but it was clear that far more information was needed," write authors Ya You (College of Charleston), Gautham G. Vadakkepatt (George Mason University), and Amit M. Joshi (University of Central Florida). "The current study hypothesized that additional platforms such as blogs, ...

High-energy TV commercials: Too much stress for consumers?

2015-03-24
Consumers are tuning out TV commercials, making advertisers run louder, higher-energy ads to force their attention. This may be backfiring critically when consumers are watching sad or relaxing shows, according to a new study in the Journal of Marketing. "This research stands to fundamentally change the ways advertisers approach the use of commercials," write authors Nancy M. Puccinelli (Oxford University), Keith Wilcox (Columbia University), and Dhruv Grewal (Babson College). "Firms will realize substantially greater success if they use moderately energetic commercials ...

Women with diabetes more likely to be diagnosed with advanced stage breast cancer

2015-03-24
TORONTO, March 24, 2015 -- Diabetes is associated with more advanced stage breast cancer, according to a new study by the Institute for Clinical Evaluative Sciences (ICES) and Women's College Hospital. The findings, published today in the journal Breast Cancer Research and Treatment, confirm a strong link between diabetes and later stage breast cancer at diagnosis for Canadian women. "Our findings suggest that women with diabetes may be predisposed to more advanced stage breast cancer, which may be a contributor to their higher cancer mortality," said Dr. Lorraine ...

Enriching the diet of calves by using flax seeds improves nutritional quality

2015-03-24
How can beef be made healthier for consumption purposes? This question has been answered by Inmaculada Gómez-Bastida in her PhD thesis, read at the NUP/UPNA-University of Navarre. When ingredients rich in n-3 polyunsaturated fatty acids, like flax seeds, and CLA (Conjugated Linoleic Acid) were added to the food of these animals, their fat was modified, achieving an increase in omega-3 fatty acids and CLA -regarded as being beneficial for health- and a reduction in saturated fatty acids linked to cardiovascular disease. "Adding flax seeds and CLA to the diet of calves," ...

LAST 30 PRESS RELEASES:

New microscope captures large, high-resolution images of curved samples in single snapshot

SwRI, UT San Antonio will test technology designed to support extended space missions to Moon, Mars

Hot flashes can be reliably predicted by an ai-driven algorithm developed by UMass Amherst and Embr Labs

FAU/Baptist Health AI spine model could transform lower back pain treatment

CDI Lab, HMH specialists identify vital pathway initiating cellular immunity in Science Immunology journal

University of Pennsylvania professor to receive the 2025 Clinical Research Prize

Revolutionary scandium doping technique extends sodium-ion battery life

High-fat diet impairs memory formation by reducing autophagy

Keck Hospital of USC named a Vizient Top Performer for third year in a row

New CRISPR test could make tuberculosis screening as simple as a mouth swab

Three-sensor overeating detection could reshape obesity treatment

Study provides first evidence that plastic nanoparticles can accumulate in the edible parts of vegetables

AI predicts complications from surgery better than doctors

New personalized risk score could improve ovarian cancer detection

People on Ozempic who eat to regulate emotions less likely to lose weight

AACR Cancer Progress Report highlights lifesaving impact of federal investments in cancer research

Indra's internet

Lymph nodes found to be key to successful cancer immunotherapy

Room-temperature terahertz device opens door to 6G networks

A hard look at geoengineering reveals global risks

When smoke signals danger: How Australian lizards evolved to escape fire

Beyond the surface: Atopic eczema linked to significantly higher risk of suicidal thoughts, major study finds

After weight loss regular exercise rather than GLP-1 weight-loss drug reduces leading cause of heart attack and strokes

EASD launches its first ever clinical practice guideline – the world’s first to focus on diabetes distress

Semaglutide provides powerful protection against diabetic retinopathy, the leading cause of blindness in working-age adults, Greek study suggests

Orforglipron taken orally once daily leads to significant body weight loss (ATTAIN-1 Study)

U of I researchers trace genetic code’s origins to early protein structures

Disease experts team up with Florida Museum of Natural History to create a forecast for West Nile virus

Researchers: Targeted efforts needed to stem fentanyl crisis

New UMaine research could help lower prescription drug costs

[Press-News.org] New kind of 'tandem' solar cell developed
Researchers combine 2 types of photovoltaic material to make a cell that harnesses more sunlight