Subscribe to our free daily newsletters
  Solar Energy News  




Subscribe to our free daily newsletters



SOLAR DAILY
Ultra-thin solar cells can easily bend around a pencil
by Staff Writers
Washington DC (SPX) Jun 24, 2016


Ultra-thin solar cells are flexible enough to bend around small objects, such as the 1mm-thick edge of a glass slide, as shown here. Image courtesy Juho Kim, et al/ APL. For a larger version of this image please go here.

Scientists in South Korea have made ultra-thin photovoltaics flexible enough to wrap around the average pencil. The bendy solar cells could power wearable electronics like fitness trackers and smart glasses. The researchers report the results in the journal Applied Physics Letters, from AIP Publishing.

Thin materials flex more easily than thick ones - think a piece of paper versus a cardboard shipping box. The reason for the difference: The stress in a material while it's being bent increases farther out from the central plane. Because thick sheets have more material farther out they are harder to bend.

"Our photovoltaic is about 1 micrometer thick," said Jongho Lee, an engineer at the Gwangju Institute of Science and Technology in South Korea. One micrometer is much thinner than an average human hair. Standard photovoltaics are usually hundreds of times thicker, and even most other thin photovoltaics are 2 to 4 times thicker.

The researchers made the ultra-thin solar cells from the semiconductor gallium arsenide. They stamped the cells directly onto a flexible substrate without using an adhesive that would add to the material's thickness. The cells were then "cold welded" to the electrode on the substrate by applying pressure at 170 degrees Celcius and melting a top layer of material called photoresist that acted as a temporary adhesive. The photoresist was later peeled away, leaving the direct metal to metal bond.

The metal bottom layer also served as a reflector to direct stray photons back to the solar cells. The researchers tested the efficiency of the device at converting sunlight to electricity and found that it was comparable to similar thicker photovoltaics. They performed bending tests and found the cells could wrap around a radius as small as 1.4 millimeters.

The team also performed numerical analysis of the cells, finding that they experience one-fourth the amount of strain of similar cells that are 3.5 micrometers thick.

"The thinner cells are less fragile under bending, but perform similarly or even slightly better," Lee said.

A few other groups have reported solar cells with thicknesses of around 1 micrometer, but have produced the cells in different ways, for example by removing the whole substract by etching.

By transfer printing instead of etching, the new method developed by Lee and his colleagues may be used to make very flexible photovoltaics with a smaller amount of materials.

The thin cells can be integrated onto glasses frames or fabric and might power the next wave of wearable electronics, Lee said.

Research paper: "Ultra-thin Flexible GaAs Photovoltaics in Vertical Forms Printed on Metal Surfaces without Interlayer Adhesives," is authored by Juho Kim, Jeongwoo Hwang, Kwangsun Song, Namyun Kim, Jae Cheol Shin and Jongho Lee. It will be published in the journal Applied Physics Letters on June 20, 2016 (DOI: 10.1063/1.4954039).


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
American Institute of Physics
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

Previous Report
SOLAR DAILY
Imec demonstrates bifacial solar cells with near 100% bifaciality
Munich, Germany (SPX) Jun 23, 2016
Imec, the world-leading nano-electronics research center and partner in Energyville, will present at this week's Intersolar Europe/EU PVSEC a highly efficient bifacial n-PERT (BiPERT) solar cell featuring a bifaciality value close to 100%. With arear cell efficiency close to the efficiency measured from the front of the cell, imec's new achievement underscores the ability to strongly enhance the ... read more


SOLAR DAILY
Chemists find new way to recycle plastic waste into fuel

Bioenergy integrated in the bio-based economy crucial to meet climate targets

New 3-D printed polymer can convert methane to methanol

Chemicals from wood waste

SOLAR DAILY
How insights into human learning can foster smarter artificial intelligence

Computers eyeing the jobs of sports camera operators

First teams named for shot at Level 2 Sample Return Robot Challenge

China's Midea begins takeover bid for German robotics firm

SOLAR DAILY
How China can ramp up wind power

Scotland investing more in offshore wind

Gamesa, Siemens join forces to create global wind power leader

Renewables getting cheaper, report finds

SOLAR DAILY
German prosecutors open probe into VW ex-boss

Electric vehicles just starting to make a splash

Volkswagen places question mark over future of diesel technology

US authorities extend deadline for VW in 'dieselgate' scandal

SOLAR DAILY
Loofah-based material could give lithium batteries a boost

Stanford researchers find new ways to make clean hydrogen and rechargable zinc batteries

Efficient hydrogen production made easy

Storage technologies for renewable energy can pay off

SOLAR DAILY
California nuclear power coming to an end

Launch of Arktika Ship Shows Russia's Ability to Churn Out Icebreakers

Southern Research launches 'Gen IV' nuclear power effort with key hire

Proposed bilateral deal allows US to share nuclear reactors with Norway

SOLAR DAILY
Norway MPs vote to go carbon neutral by 2030

Algorithm could help detect and reduce power grid faults

It pays to increase energy consumption

Changing the world, 1 fridge at a time

SOLAR DAILY
Scores of environmental activists murdered in 2015: report

EU at loggerheads with Poland over World Heritage forest

Honduras protest demands international probe into activist's murder

European droughts hit British trees the hardest




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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