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Conjugated polymers, like this one here, are special organic molecules which exhibit special quantum effects which help them transfer electrons like a semiconductor. This makes them a perfect candidate for cheap organic solar cells and circuits, as well as a possible building block for quantum computers.  (Source: University of Bath)
New U of T research looks to create organic solar cells by using special quantum effect

Imagine having cheap, printable solar cells at your fingertips, woven into your clothing, streaming power into your mobile electronics.  Organic electronics, a field which includes organic solar cells and organic transistor circuits, has many advantages, the biggest of which is the ability to be printed easily, and the ability to flex without breaking.

Greg Scholes and Elisabetta Collini of University of Toronto's Department of Chemistry have discovered the mechanism behind how light triggers the transport of electricity in one promising organic solar material.  Their new discovery could be applied to producing cheaper and more efficient cells.

The team looked at conjugated polymers, one of the most efficient organic materials available for solar power production.  These long molecules can be also used in transistors and LEDs.  They behave roughly like semiconductors, while retaining important organic characteristics.  When exposed to light, they produce energy, which is transferred down their chain, eventually reaching other molecules and finally leaving the cell.

However, the way this transfer occurs was poorly understood, until now, making it difficult to optimize.  Explains Professor Collini, "One of the biggest obstacles to organic solar cells is that it is difficult to control what happens after light is absorbed: whether the desired property is transmitting energy, storing information or emitting light.  Our experiment suggests it is possible to achieve control using quantum effects, even under relatively normal conditions."

Her colleague, Professor Scholes describes this quantum effect responsible for the transmission, noted, "We found that the ultrafast movement of energy through and between molecules happens by a quantum-mechanical mechanism rather than through random hopping, even at room temperature.  This is extraordinary and will greatly influence future work in the field because everyone thought that these kinds of quantum effects could only operate in complex systems at very low temperatures."

As well as being a breakthrough for organic electronics, the discovery could also yield advances in quantum computing.  One of the key obstacles currently in quantum computing is the ultra-low temperatures needed to maintain useful quantum effects.  The discovery of such effects occurring at room temperature could lead to important breakthroughs in building quantum computers.

On a technical level, the team used bursts from an ultrashort laser to trigger atoms of the polymer into a quantum-mechanical state.  In this state the atoms were simultaneously in the ground state and at the energy level of the absorb photon.  This phenomenon is a type of superposition known as quantum coherence.  They used more lasers and a sophisticated measuring technique to then determine if the quantum state was being transferred between atoms on the chain. 

Describes Professor Scholes, "It turns out that it only moves along polymer chains.  The chemical framework that makes up the chain is a crucial ingredient for enabling quantum coherent energy transfer. In the absence of the chemical framework, energy is funneled by chance, rather than design.  This means that a chemical property – structure -- can be used to steer the ultrafast migration of energy using quantum coherence. The unique properties of conjugated polymers continue to surprise us."

The findings are reported in the Jan. 16 edition of the journal Science. The work was sponsored by the Natural Sciences and Engineering Research Council of Canada.



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Oh, cool
By ninus3d on 1/16/2009 3:16:18 PM , Rating: 2
quote:
Conjugated polymers, like this one here, are special organic molecules which exhibit special quantum effects which help them transfer electrons like a semiconductor.


Just gotta say, that is indeed quite cool!
Never heard of this kinds of things before.




RE: Oh, cool
By Master Kenobi (blog) on 1/16/2009 3:27:47 PM , Rating: 2
Once they start talking about quantum effects it means they know it does it, but haven't a clue why exactly since just about everything quantum is labed as such due to its logic defying properties.


RE: Oh, cool
By masher2 (blog) on 1/16/2009 4:51:54 PM , Rating: 5
On a mathematical basis, quantum mechanics (QM) and quantum electrodynamics (QED) are extremely well-understood and quantified branches of science. They're not just using a buzzword here.

We don't have a very good conceptual model to hang QM upon, but the effects of quantum theory are very well understood.


RE: Oh, cool
By foolsgambit11 on 1/16/2009 8:08:08 PM , Rating: 2
But it's very difficult to calculate complex modeling scenarios in QM. We understand simple modeling of quantum effects well, but something like harnessing energy from complex organic molecules would take a ridiculous amount of computation to optimize.


RE: Oh, cool
By masher2 (blog) on 1/16/2009 10:45:50 PM , Rating: 2
You don't need the complete solution to the Schrodinger equation just to see you're getting coherence effects...nor to potentially exploit that for useful purpose.


RE: Oh, cool
By William Gaatjes on 1/17/2009 7:35:18 AM , Rating: 2
That is where i feel you go wrong. In the quantum mechanical world there can be side effects. Variables that suddenly seem to be amplified for no apparent reason. These effects do not seem to bother the experiments or practical use and thus are nullified. But as always the answer is in the details.


Nice
By PedroDaGr8 on 1/16/2009 3:28:08 PM , Rating: 3
Back as an undergrad I did research on polyfunctionalized pentacene's for use as organic solar cells and OLEDs. They were cool, they were a deep navy blue color but glowed bright red when illuminated by a blacklight. They were so fluorescent, the stray UV from fluorescent bulbs would cause the top cm or so of a solution to glow red.

By the way, that image is of an oligomer not a polymer, it only has 3 repeating units (oligmer is commonly define as less than 10 units). I say this only because there is no spots left open to continue polymerizaiton.

That looks like an organothiophene oligomer, which means it contains sulfur so it is stinky.




RE: Nice
By codeThug on 1/16/2009 3:38:13 PM , Rating: 2
quote:
That looks like an organothiophene oligomer, which means it contains sulfur so it is stinky.


Does that mean we can't eat it?


RE: Nice
By William Gaatjes on 1/17/2009 7:43:19 AM , Rating: 2
If you like garlic you like sulphur too.

There seems to be some connection beween Sulphur combined with other elements and the immune system.


RE: Nice
By sld on 1/17/2009 9:47:03 AM , Rating: 2
I thought that was selenium, not sulphur...


RE: Nice
By William Gaatjes on 1/19/2009 2:33:50 PM , Rating: 2
quote:
I thought that was selenium, not sulphur...


You and i are right. It's both selenium and sulphur compounds as several vitamins it seems. But i am going by what i have read tho. I like garlic (and yes i make sure after eating garlic rich food i do some brushing and mouthwashing) but i am not a specialist.


Dumb Question...
By acase on 1/16/09, Rating: 0
RE: Dumb Question...
By amanojaku on 1/16/2009 5:12:43 PM , Rating: 2
That would be impossible. Let's assume that you were able to find materials that would allow for the loss-less absorption and re-emission of the generated light from bulb to collector back to bulb. Since energy can neither be created nor destroyed you would need the same amount of energy flowing through this "circuit" to keep it going. If light is shining AWAY from the collector that means the circuit has sprung a leak. Eventually you would run out of power.


RE: Dumb Question...
By Jellodyne on 1/16/2009 5:44:53 PM , Rating: 3
Lisa, in this household we obey the laws of thermodynamics!


RE: Dumb Question...
By Gzus666 on 1/16/2009 6:24:53 PM , Rating: 2
http://en.wikipedia.org/wiki/Conservation_of_energ...

Conservation laws are your friends. You are basically proposing the "perpetual motion machine" in electrical form.


RE: Dumb Question...
By 306maxi on 1/16/2009 8:13:43 PM , Rating: 2
I bet when you read that back you'll think "Did I really say that?"

As others have pointed out it's impossible.


Organic solar cells
By bobsmith1492 on 1/16/2009 3:33:43 PM , Rating: 2
Organic solar cells are nothing new, by the way.

For example: http://en.wikipedia.org/wiki/File:Brassica_rapa_pl...

There are many others of different shapes and sizes. They can even be used to generate electricity directly: http://www.7gadgets.com/wp-content/uploads/2007/10...




RE: Organic solar cells
By omnicronx on 1/16/2009 3:51:26 PM , Rating: 3
quote:
Organic solar cells are nothing new, by the way.
The article pretty much points this out, the point here is that they now know they can control the movement of energy in ways they previous could not.
quote:
This means that a chemical property – structure -- can be used to steer the ultrafast migration of energy using quantum coherence.
Knowing why, and how this happens is a totally different matter ;)


RE: Organic solar cells
By bobsmith1492 on 1/16/2009 5:03:43 PM , Rating: 2
Very possible, but that's not the point of my post... ;)


Harvesting the sun's energy with antennas
By nesivos on 1/16/2009 7:23:06 PM , Rating: 2
An economical alternative

Commercial solar panels usually transform less that 20 percent of the usable energy that strikes them into electricity. Each cell is made of silicon and doped with exotic elements to boost its efficiency. "The supply of processed silicon is lagging, and they only get more expensive," Novack says. He hopes solar nanoantennas will be a more efficient and sustainable alternative.

The team estimates individual nanoantennas can absorb close to 80 percent of the available energy. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that's commonly used in bags and plastic wrap. In fact, the team first printed antennas on plastic bags used to deliver the Wall Street Journal, because they had just the right thickness.

By focusing on readily available materials and rapid manufacturing from inception, Novack says, the aim is to make nanoantenna arrays as cheap as inexpensive carpet.

https://inlportal.inl.gov/portal/server.pt?open=51...




RE: Harvesting the sun's energy with antennas
By 90014 on 1/20/2009 11:12:27 PM , Rating: 2
There's a group of Ohio State University chemists that, through non-organic materials, is able to include the UV and IR spectrum when converting light to energy. Theirs seems just as flexible as above, though on plastic. They claim that by including all three spectrum they can archive 99.999% efficiency. My question is how is achieving solar energy by organic means going to top what they call the 'triplet state' for a period of 200 microseconds resulting in very high output?


By 90014 on 1/20/2009 11:43:25 PM , Rating: 2
"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates














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