This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Share this

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – brightrecruits.com can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today

Blog

Here comes the Sun

Monday.jpg
Marc Baldo shines light on phycobilisomes

By Hamish Johnston

It’s a dull morning here in Pittsburgh — and the view out the press room window is of a rusting railway viaduct, grey pavement, hills covered in leafless brown trees and a leaden sky.

However in a couple of months it will be hot and hazy here as the city basks under a Mediterranean-strength Sun. You might think this would make Pittsburgh a perfect place to deploy solar panels (at least in the summer) — but there is a problem, all that haze makes it difficult to focus sunlight onto high-performance photovoltaics.

This focussing is necessary because it is very difficult to make large-area photovoltaics from semiconductors. The materials and processing are expensive and it is tricky to make large devices without defects, which reduce their efficiency.

One solution is to simply use an optical system of lenses and/or reflectors to concentrate the light at a photovoltaic. The problem is that such systems must track the Sun precisely — which is tough to do when it is lurking in the haze.

A better way would be to take a hint from nature and capture diffuse light and then concentrate it on an efficient photovoltaic. However like most biomimicry, this is easier said than done.

This morning MIT’s Marc Baldo talked us through a number of approaches that he was taking in his lab. The most successful one, it seems, is using glass plates containing fluorescent dye. Sunlight enters the plate via the broadside and causes the dye to emit light. This light then travels along the plate to one edge, where it can enter a photovoltaic.

The advantage is that much of the light captured by the large broadside of the plate is re-emitted as light that leaves the plate via the much smaller edges — concentrating it where it can be converted to electricity by a relatively small photovoltaic.

However, Baldo and team had to cleverly engineer the energy levels in the dye to ensure that the light destined for the phovoltaic is not reabsorbed and ultimately scattered out of the plate.

This is done using a molecules called phycobilisomes — proteins that are involved in photosynthesis.

Hopefully this will allow Baldo’s devices to be a bit more like plants — not solid chunks of semiconductor — by separating the functions of light absorbtion ad charge production.

This entry was posted in APS March Meeting 2009. Bookmark the permalink.
View all posts by this author  | View this author's profile

Leave a comment

Your e-mail address will not be published. Required fields are marked *

Guidelines

  • Comments should be relevant to the article and not be used to promote your own work, products or services.
  • Please keep your comments brief (we recommend a maximum of 250 words).
  • We reserve the right to remove excessively long, inappropriate or offensive entries.

Show/hide formatting guidelines

Tag Description Example Output
<a> Hyperlink <a href="http://www.google.com">google</a> google
<abbr> Abbreviation <abbr title="World Health Organisation" >WHO</abbr> WHO
<acronym> Acronym <acronym title="as soon as possible">ASAP</acronym> ASAP
<b> Bold <b>Some text</b> Some text
<blockquote> Quoted from another source <blockquote cite="http://iop.org/">IOP</blockquote>
IOP
<cite> Cite <cite>Diagram 1</cite> Diagram 1
<del> Deleted text From this line<del datetime="2012-12-17"> this text was deleted</del> From this line this text was deleted
<em> Emphasized text In this line<em> this text was emphasised</em> In this line this text was emphasised
<i> Italic <i>Some text</i> Some text
<q> Quotation WWF goal is to build a future <q cite="http://www.worldwildlife.org/who/index.html">
where people live in harmony with nature and animals</q>
WWF goal is to build a future
where people live in harmony with nature and animals
<strike> Strike text <strike>Some text</strike> Some text
<strong> Stronger emphasis of text <strong>Some text</strong> Some text
WordPress Appliance - Powered by TurnKey Linux