New world record efficiency for thin film silicon solar cells

A 10.7 percent conversion rate has been achieved using less than 2 micrometers of raw material

2013-02-12

(Press-News.org) The Photovoltaics-Laboratory (PV-Lab) of EPFL's Insitute of Microengineering (IMT), founded in 1984 by Prof. Arvind Shah and now headed by Prof. Christophe Ballif, is well known as a pioneer in the development of thin-film silicon solar cells, and as a precursor in the use of microcrystalline silicon as a photoactive material in thin-film silicon photovoltaic (TF-Si PV) devices. A remarkable step was achieved by the team led by Dr. Fanny Meillaud and Dr. Matthieu Despeisse with a new world record efficiency of 10.7% for a single-junction microcrystalline silicon solar cell, independently confirmed at Fraunhofer Institute for Solar Energy Systems (ISE CalLab PV Cells) in Freiburg (Germany).

"Deep understanding has been gained these last years in material quality, efficient light-trapping and cell design, which in combination with careful process optimization led to this remarkable world-record efficiency" says Simon Hänni, PhD student at IMT Neuchâtel. Importantly, the employed processes can be up-scaled to the module level. While standard wafer-based crystalline silicon PV technology implements absorber layers with a thickness of about 180 micrometers for module conversion efficiency of 15 to 20%, 10.7% efficiency was reached here with only 1.8 micrometers of silicon material, i.e. 100 times less material than for conventional technologies, and with cell fabrication temperature never exceeding 200°C.

Thin-film silicon technology indeed offers the advantages of saving up on raw material and offering low energy payback time, thus allowing module production prices as low as 35 €/m2, reaching the price level of standard roof tiles.

The reported progress is of paramount importance for increasing further TF-Si PV devices efficiency and potential, as at least one microcrystalline silicon junction is systematically used in combination with an amorphous silicon junction to form multiple junction devices for a broader use of the solar spectrum. The reported record efficiency clearly indicates that the potential of TF-Si multi-junction devices can be extended to > 13.5% conversion efficiency with a minimum usage of abundant and non-toxic raw material at low costs (TF-Si PV modules implementing in their simplest form two glasses and few microns of zinc and of silicon for an easy recycling).

### Work leading to this result was supported by the Swiss Federal Office of Energy (SFOE), the EU-FP7 program, the Swiss National Science Foundation (SNSF) and the Commission for Technology and Innovation (CTI).

ELSE PRESS RELEASES FROM THIS DATE:

Depression risk among women in the military deployed after childbirth

2013-02-12

New Rochelle, NY, February 12, 2013—About 16,000 women on active duty in the U.S. military give birth each year. Most return to service after 6 weeks and can be deployed after 4 months. The potential for an increased risk of depression among new mothers who deploy and are exposed to combat experience is presented in a study published in Journal of Women's Health, a peer-reviewed publication from Mary Ann Liebert, Inc., publishers. The article is available free on the Journal of Women's Health website at http://www.liebertpub.com/jwh. Stacie Nguyen, MPH and coauthors from ...

New material promises better solar cells

2013-02-12

This press release is available in German. Single atomic layers are combined to create novel materials with completely new properties. Layered oxide heterostructures are a new class of materials, which has attracted a great deal of attention among materials scientists in the last few years. A research team at the Vienna University of Technology, together with colleagues from the USA and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells. Discovering New Material Properties in Computer ...

Study shows long-term success rates for eradication of Barrett's esophagus after endoluminal therapies

2013-02-12

OAK BROOK, Ill. – February 12, 2013 – A new study from researchers at the Hospital of the University of Pennsylvania reports that endoluminal (endoscopic) therapies, combining resection and ablation techniques, for patients with Barrett's esophagus and high-grade dysplasia or early mucosal cancer have a high success rate, with durable results and a low risk of complications. The researchers noted that endoscopic surveillance after successful eradication is required. The study appears in the February issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific ...

Crew rotation and passenger connections spread flight delays

2013-02-12

This press release is available in Spanish. A study led by researchers of the Spanish National Research Council and the University of the Balearic Islands asserts that crew rotation and passengers connections systematically spread flight delays due to a domino effect. The work, that proposes a new methodology to assess the degree of air traffic congestion, is published on the latest issue of Scientific Reports. The study, based on data collected by the Federal Aviation Administration of the United States, provides a tool to evaluate airlines planning and confirms that ...

Cheap, strong lithium-ion battery developed at USC

2013-02-12

Researchers at USC have developed a new lithium-ion battery design that uses porous silicon nanoparticles in place of the traditional graphite anodes to provide superior performance. The new batteries—which could be used in anything from cell phones to hybrid cars—hold three times as much energy as comparable graphite-based designs and recharge within 10 minutes. The design, currently under a provisional patent, could be commercially available within two to three years. "It's an exciting research. It opens the door for the design of the next generation lithium-ion batteries," ...

Model aims to help companies make products we actually want

2013-02-12

Researchers have developed a model that will, hopefully, help companies develop innovative products that people actually want to use. The model is a first step towards capturing the behavior of both companies and consumers, so that we end up with more iPods and fewer Edsels. This concept may sound obvious, but companies have difficulty grasping it. Companies constantly try to develop new products and services that capture market share. We knew that. Consumers constantly try to evaluate recent innovations to determine whether they're useful, and how much they'd be willing ...

Can therapy dogs be beneficial for children with autism spectrum disorder?

2013-02-12

New Rochelle, NY, February 12, 2013—About 1 in 150 children are affected by an autism spectrum disorder (ASD), a group of neurodevelopmental disorders characterized by difficulty with language, communication, and social interaction. A critical review of several published studies evaluating the potential for therapy or assistance dogs to help children with ASD overcome some of these challenges is published in The Journal of Alternative and Complementary Medicine, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free on the Journal ...

Middle East river basin has lost Dead Sea-sized quantity of water

2013-02-12

Irvine, Calif., Feb. 12, 2013 – Already strained by water scarcity and political tensions, the arid Middle East along the Tigris and Euphrates rivers is losing critical water reserves at a rapid pace, from Turkey upstream to Syria, Iran and Iraq below. Unable to conduct measurements on the ground in the politically unstable region, UC Irvine scientists and colleagues used data from space to uncover the extent of the problem. They took measurements from NASA's Gravity Recovery and Climate Experiment satellites, and found that between 2003 and 2010, the four nations lost ...

A system that improves the precision of GPS in cities by 90 percent

2013-02-12

This press release is available in Spanish. VIDEO: Researchers at Universidad Carlos III de Madrid have developed a new system which improves the ability of a GPS to determine a vehicle’s position as compared to that of conventional... Click here for more information. Researchers at Universidad Carlos III de Madrid have developed a new system which improves the ability of a GPS ...

Nature Methods study: Using light to control cell clustering

2013-02-12

Troy, N.Y. – A new study from engineers at Rensselaer Polytechnic Institute and the University of California, Berkeley, pairs light and genetics to give researchers a powerful new tool for manipulating cells. Results of the study, published in the journal Nature Methods, show how blue light can be used as a switch to prompt targeted proteins to accumulate into large clusters. This process of clustering, or oligomerization, is commonly employed by nature to turn on or turn off specific signaling pathways used in cells' complex system of communications. The new study details ...

LAST 30 PRESS RELEASES:

Puzzling link between depression and cardiovascular disease explained at last: they partly develop from the same gene module

Synthetic droplets cause a stir in the primordial soup

Future parents more likely to get RSV vaccine when pregnant if aware that RSV can be a serious illness in infants

Microbiota enterotoxigenic Bacteroides fragilis-secreted BFT-1 promotes breast cancer cell stemness and chemoresistance through its functional receptor NOD1