Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Solar Energy News .




SOLAR DAILY
Future looks bright for carbon nanotube solar cells
by Staff Writers
Madison WI (SPX) Jun 24, 2013


Light from the sun creates charges in an ultrathinfilm of carbon nanotubes (blue), which are extracted by fullerene C60 (brown) in this schematic of the groundbreaking proof-of-concept solar cell with greater than 1 percent efficiency.

In an approach that could challenge silicon as the predominant photovoltaic cell material, University of Wisconsin-Madison materials engineers have developed an inexpensive solar cell that exploits carbon nanotubes to absorb and convert energy from the sun.

The advance could lead to solar panels just as efficient, but much less expensive to manufacture, than current panels.

The proof-of-concept carbon nanotube solar cell can convert nearly 75 percent of the light it absorbs into electricity, says Michael Arnold, an assistant professor of materials science and engineering at UW-Madison and a pioneer in developing carbon nanotube-based materials for solar energy applications. "We've made a really fundamental key step in demonstrating that it will be possible to use these new carbon nanotube materials for solar cells one day," he says.

Arnold and Ph.D student Matthew Shea described the development in a paper published June 17 in the online edition of the journal Applied Physics Letters.

Silicon is abundant and an efficient solar energy gatherer, yet is expensive to process and manufacture into solar panels. As a result, researchers are studying alternative materials - among them, carbon nanotubes.

Recent advances have afforded researchers a greater level of control over the chemical makeup of carbon nanotubes, which in turn has opened the door to myriad applications. The thin spaghetti-like tubes are easy and inexpensive to manufacture, stable and durable, and are both good light absorbers and electrical conductors.

Much of the current carbon nanotube solar cell research centers around proven solar cell materials that use mixed-in nanotubes to conduct the electrical charge. "That's only using half the capabilities that nanotubes offer," says Arnold, whose prior work with carbon nanotubes for transistors inspired him to explore applications in solar energy.

Building on a half-decade of research, including foundational studies by Ph.D student Dominick Bindl, Arnold and Shea developed a solar cell that uses carbon nanotubes to collect light and convert it to electricity.

"We're starting from the ground up and trying to get high efficiency out of the nanotubes," says Arnold. "We're trying to get as much power conversion as possible out of our material, and that's what's unique about our work."

Essentially, the proof-of concept solar cell is an ultrathin sheet, or film, of carbon nanotubes layered atop another thin sheet of a material called buckminsterfullerene, or C60. The nanotubes absorb the bulk of the sunlight and retain the positive charge, while the C60 draws the negative charge.

Solar cell efficiency is the percentage of solar energy shining on a cell that the cell actually converts into electrical energy. When Arnold and his students began this research five years ago, their solar cells achieved power-conversion efficiencies of only about a millionth of a percent. Today - in contrast with the 15-percent average efficiency of conventional silicon solar cells - their proof of concept is 1 percent efficient.

While that number might seem low, Arnold is optimistic it can rise - in part because the sun-catching carbon nanotube layer of the proof-of-concept solar cell is just a few atoms thick. And, the cell converts approximately 75 percent of the sunlight it absorbs into electricity. "Of the light that is absorbed, we're converting most of it," says Arnold.

The next step in boosting that efficiency already is underway. The researchers now are focusing on augmenting the thickness of the carbon nanotube thin film from a mere 5 nanometers to at least 100 - which, according to their theoretical models, ultimately could put the power-conversion efficiency of their solar cells in line with that of silicon cells. "What our work shows is that you will be able to get as high efficiency as silicon eventually, and that's why we're excited," says Arnold.

Arnold received funding for the research from the Army Research Office.

.


Related Links
University of Wisconsin-Madison
All About Solar Energy at SolarDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SOLAR DAILY
EU trade chief sees speedy end to China solar row
Beijing (AFP) June 21, 2013
The European Union's trade chief expressed confidence Friday that Brussels and Beijing can reach a speedy agreement in a bitter dispute over Chinese solar panels that sparked fears of a debilitating trade war. "I trust that we can come to a solution in the coming days or coming weeks," EU Trade Commissioner Karel De Gucht said at a press conference in Beijing. His remarks came after the ... read more


SOLAR DAILY
Novel Enzyme from Tiny Gribble Could Prove a Boon for Biofuels Research

A cheaper drive to 'cool' fuels

When green algae run out of air

An environmentally friendly battery made from wood

SOLAR DAILY
A robot that runs like a cat

Robot that runs like a cat springs to life in Switzerland

When Will My Computer Understand Me

Space droids calling

SOLAR DAILY
Spanish downturn a disaster for green energy

New certified small wind turbine announced for US market

Mongolia confronts smog with launch of first wind farm

New certified small wind turbine announced for US market

SOLAR DAILY
Arnie defends his Hummer fleet as eco-friendly

Wolf urine, lion's roar keep deer from Japan transport

Tesla recalls Model S cars over problem weld

US auto giant GM plans to invest $11 billion in China

SOLAR DAILY
Fracking raises risk of contaminated drinking water: study

Iraq oil exports dip on weather, sabotage

Oil prices ease on US, China concerns

Stray gases found in water wells near shale gas sites

SOLAR DAILY
New radioactive water leak at Fukushima: TEPCO

US state in new alert over nuclear waste leak

Romania to sell stake in nuclear plant operator

Poland may delay launch of nuclear plants: PM

SOLAR DAILY
John Kerry promotes clean energy in India

EU Parliament committee passes revised emissions trading scheme fix

World cities improving energy efficiency: report

China launches first carbon trading scheme

SOLAR DAILY
The contribution of particulate matter to forest decline

Whitebark Pine Trees: Is Their Future at Risk

Brazil's restive natives step protests over land rights

Brazilian official resigns over indigenous protests




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement