Monday, May 21, 2007

The Silver Bullet


Here is another major announcement in photon to electron conversion materials. This one comes from Rice University.

Quantum dot recipe may lead to cheaper solar panels

Rice scientists clear hurdle on path to nanotech-based photovoltaics

Rice University scientists today revealed a breakthrough method for producing molecular specks of semiconductors called quantum dots, a discovery that could clear the way for better, cheaper solar energy panels.

The research, by scientists at Rice's Center for Biological and Environmental Nanotechnology (CBEN), appears this week in the journal Small. It describes a new chemical method for making four-legged cadmium selenide quantum dots, which previous research has shown to be particularly effective at converting sunlight into electrical energy.

"Our work knocks down a big barrier in developing quantum-dot-based photovoltaics as an alternative to the conventional, more expensive silicon-based solar cells," said paper co-author and principal investigator Michael Wong, assistant professor of chemical and biomolecular engineering.

Quantum dots are "megamolecules" of semiconducting materials that are smaller than living cells. They interact with light in unique ways, to give off different-colored light or to create electrons and holes, due partly to their tiny size, partly to their shape and partly to the material they're made of.

Scientists have studied quantum dots for more than a decade, with an eye toward using them in medical tests, chemical sensors and other devices.
One way towards cheaper solar cells is to make them out of quantum dots. Prior research by others has shown that four-legged quantum dots, which are called tetrapods, are many times more efficient at converting sunlight into electricity than regular quantum dots.

But, Wong said the problem is that there is still no good way of producing tetrapods.

Current methods lead to a lot of particles with uneven-length arms, crooked arms, and even missing arms. Even in the best recipe, 30 percent of the prepared particles are not tetrapods, he said. (clip)

"One of the major bottlenecks in developing tetrapod-based solar cell devices has been removed, namely the unavailability of high-quality tetrapods of the cadmium selenide kind," Wong said. "We might be able to make high-quality nanoshapes of other compositions also, using this new synthesis chemistry."

Over and and over, I have often heard it said,

There is no "one" silver bullet.

It's repeated in renewable circles like a mantra.

Instead of dilly dallying around with so many other

never ending non-solutions to the challenges we face,

Maybe we should find one, and

Settle on it.

Develop it.

Deploy it.

And enjoy the peace and prosperity it will bring.





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2 Comments:

Anonymous zahir said...

Dear friends,

In one of your previous postings on the environment and global warming, I had noted some skepticism on the sudden resurgence of this 'sky is falling' mantra in the popular press.

Just fyi - I saw this article today: "Climate Momentum Shifting: Prominent Scientists Reverse Belief in Man-made Global Warming - Now Skeptics"

http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=927b9303-802a-23ad-494b-dccb00b51a12&Region_id=&Issue_id


Could you perhaps comment on this report?

It seems to argue the converse of what the popular media and other institutional scientists, as well as your own writings have been arguing recently.

Sorry that it's a bit unrelated to your current story.

Thanks.
Zahir

11:21 AM  
Blogger OZ said...

Your relying on Sen Inhofe's blog.

Not exactly a reliable source.

Stay with the real science not the politics of the Oklahoma Oil and Gas Senator who will go down as one of the great goof balls of Senate history.

Time is of the essense.

The sky IS falling, and if you follow the science and not the propaganda, you too will likely come to the same conclusion.

Thanks for the comment.

12:52 PM  

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