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PJames
In this case you'd probably want to aim for exactly the opposite... something ...
bensham
Look carefully at real, manufacturable efficiencies. They are far less than what ...
Dark discovery could double solar cell efficiency
Peter Clarke
12/23/2011 8:39 AM EST
LONDON – The efficiency of solar cells could be doubled by the discovery of a quantum "shadow state" that allows two – rather than one – high-energy electrons to be produced by optoelectronic energy conversion. The latest research on the mechanisms of solar energy conversion was led by chemistry Professor Xiaoyang Zhu at The University of Texas at Austin and was published in Science magazine.
Zhu and his team have discovered that it's possible to double the number of electrons harvested from one photon of sunlight using pentacene, an organic plastic semiconductor material.
"Plastic semiconductor solar cell production has great advantages, one of which is low cost," said Zhu, in a statement. "Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies."
The maximum theoretical efficiency of the silicon solar cell in use today is approximately 31 percent. This is because much of the photonic energy hitting the cell is not that at wavelengths that can be turned into usable electricity. That energy is instead lost as heat. Capturing the thermally excited hot electronic energy could potentially increase the efficiency of solar-to-electric power conversion to as high as 66 percent, according to the research team.
Zhu and his team previously demonstrated that those hot electrons could be captured using semiconductor nanocrystals. They published that research in Science in 2010, but Zhu says the actual implementation of a viable technology based on that research is very challenging. The primary one being that it requires focused sunlight rather than ambient light that typically hits a solar panel.
Zhu and his team have found an alternative. They discovered that in the semiconductor pentacene a photon produces a dark quantum "shadow state" from which two electrons can then be efficiently captured to generate more energy.
The absorption of a photon creates an excited electron-hole pair, called an exciton. The exciton is coupled quantum mechanically to a dark "shadow-state" called a multi-exciton. It so happens that the multi-exciton can be an efficient source of two electrons via transfer to an electron acceptor material such as fullerene, the ball-shaped 60-atom allotrope of carbon, which was used in the study. Exploiting this could raise pentacene solar cell efficiency to 44 percent without the need for a focused solar beam, according to the researchers.
The research team was led by Wai-lun Chan, a postdoctoral fellow in Zhu's group, with the help of postdoctoral fellows Manuel Ligges, Askat Jailaubekov, Loren Kaake and Luis Miaja-Avila.
Related links and articles:
Dark state announcement
News articles:
Heliatek achieves 9.8 percent organic solar cell efficiency
Solar firm claims efficiency record
Sharp claims world's highest solar cell conversion efficiency of 35.8 percent
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DrQuine
12/23/2011 10:25 AM EST
It is unexpected discoveries like these that offer the potential for cost effective solar power generation - and can render the currently leading technology obsolete overnight. A scary place to be investing but an exciting time for the future of affordable distributed power generation.
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wilber_xbox
12/23/2011 11:01 AM EST
this is pretty cool discovery. If a commercial viability can be found then it can be a game changer for the solar cells. Article worth forwarding to clean energy enthusiasts.
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Dr DSP
12/23/2011 2:33 PM EST
Sharp shows 35.8% efficiency. Even getting to 50% would be a big plus. Is there a good chart showing efficiency growth over time anyone knows of?
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goafrit
12/23/2011 3:29 PM EST
Let us see - in this sector, we have always had this nice expectation only to be disappointed. But this one could be real.
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Dave.Dykstra
12/24/2011 12:06 AM EST
Let's hope this one is really a breakthrough that can be economically employed. That could give a real boost to this sector of the industry and, ultimately, to the consumer.
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Sanjib.Acharya
12/24/2011 4:21 AM EST
Lower cost with double the efficiency!! This seems to be first one of the breakthrough discoveries that is very much needed to take the solar power generation to the next milestone. Is there a plan to build a solar panel to demonstrate the efficiency that could be derived once it is produced commercially?
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agk
12/24/2011 7:05 AM EST
present is 36% efficiency. the new research here is for 44%. By about 8%. This the next major step towards higher efficiency. Low cost also. Coommercialisation will be fruitfull. So by 5 more years we reach about 60 to 70% efficiency.I forsee a great solar future in our earth planet.
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wilber_xbox
12/24/2011 9:46 AM EST
yeah, i think plastic and organic are major ways to reduce cost. Silicon processing is a major hurdle for the introduction of PV solar cells.
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daleste
12/24/2011 1:21 PM EST
From 31% to 44% doesn't seem to be double to me, but increasing efficiency and reducing cost is very much needed for solar energy. I'm glad this research in going on and hope it continues.
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Andy Betts
12/25/2011 1:43 AM EST
The work seems really interesting, but the confusion in the numbers makes me think that I have missed something. The headline clearly says "double". Why double? Does this leap require the use of focused light, for example? What performance improvement can we expect from solar panels as a result of this research? Thanks for any clarification.
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http://www.lulu.com/spotlight/poconoarmchairreview
12/25/2011 12:45 PM EST
I think he was talking about doubling the theoretical efficiency. The 44% figure was the guess concerning output without focused light.
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KB3001
12/26/2011 5:32 AM EST
Definitely something to keep en eye on, as it might just be what solar needs to break through. Here is Prof. Zhu's group website by the way: http://zhu.cm.utexas.edu
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prabhakar_deosthali
12/26/2011 5:57 AM EST
For countries like Germany who pan to shout down their Nuclear power generation completely in the next decade , this news is encouraging. It tells us that Solar energy may become a economically viable and environmentally safe alternative to nuclear energy in the near future.
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hm
12/26/2011 8:05 AM EST
Advent of this technology in near future will give us ample opportunity to develop and resolve many critical applications. Looking forward for more breakthrough.
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kinnar
12/26/2011 2:22 PM EST
This is a very greatly written article, very nice precise and sufficient in terms of content.
It will be surely a very great gift to the mankind by the inventor if the commercial production of the material is possible. There also many other affecting factors a the material is being plastic.
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Robotics Developer
12/26/2011 7:45 PM EST
I wonder what the cost per watt output will be for these? I did not see any roll-out plan and was hoping for hints about pre-production date, estimated final effective efficiency, etc.. It sounds like they are moving in the right direction but still have a lot of experimenting left to do. Good luck!
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Aadil.Raja
12/27/2011 7:29 PM EST
This discovery looks very promising. However, what concerns me is the use of plastic. Not sure if this is actual "plastic", but if it is, then how could you make it degradable?
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PJames
1/5/2012 8:46 PM EST
In this case you'd probably want to aim for exactly the opposite... something that would not degrade. Having biodegradle replacements for things that are produced in huge quantities and often discarded... shopping bags, disposable plates, etc. is a great idea. An expensive device that should last as long as possible (20, 30 or more years) to make it economically feasible should simply be accepted as something that will take up a bit of room in a landfill if it can't be recycled.
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bensham
1/5/2012 2:51 PM EST
Look carefully at real, manufacturable efficiencies. They are far less than what is obtained in the lab. Typical efficiencies for commercial solar cells are in the 8% to 17% range. This discovery will be great if the gain can be seen in mass produced solar cells.
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