Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Quantum mechanics matters: First real time movies of the light-to-current conversion in an organic solar cell

Abstract:
Photovoltaic cells directly convert sun light into electricity and hence are key technological devices to meet one of the challenges that mankind has to face in this century: a sustainable and clean production of renewable energy. Organic solar cells, using polymeric materials to capture sun light, have particularly favorable properties. They are low-cost, light-weight and flexible, and their color can be adapted by varying the material composition. Such solar cells typically consist of nanostructured blends of conjugated polymers (long chains of carbon atoms), acting as light absorbers, and fullerenes (nanoscale carbon soccer balls), acting as electron acceptors. The primary and most elementary step in the light-to-current conversion process, the light-induced transfer of an electron from the polymer to the fullerene, occurs at such a staggering speed that it has previously proven difficult to follow it directly.

Quantum mechanics matters: First real time movies of the light-to-current conversion in an organic solar cell

Oldenburg, Germany | Posted on May 30th, 2014

Now, a team of German and Italian researchers from Oldenburg, Modena and Milano reported the first real time movies of the light-to-current conversion process in an organic solar cell. In a report published in the May 30 issue of Science Magazine, the researchers show that the quantum-mechanical, wavelike nature of electrons and their coupling to the nuclei is of fundamental importance for the charge transfer in an organic photovoltaic device.

"Our initial results were actually very surprising", says Christoph Lienau, a physics professor from the University of Oldenburg who led the research team. "When we used extremely short, femtosecond (1 billionth of a millionth of a second, i.e. 0.000000000000001 seconds) light pulses to illuminate the polymer layer in an organic cell, we found that the light pulses induced oscillatory, vibrational motion of the polymer molecules. Unexpectedly, however, we saw that also the fullerene molecules all started to vibrate synchronously. We could not understand this without assuming that the electronic wave packets excited by the light pulses would coherently oscillate back and forth between the polymer and the fullerene." All colleagues with whom the scientists discussed these initial results, obtained by PhD student Sarah Falke from Oldenburg in close collaboration with the team of Giulio Cerullo from Politecnico di Milano, leading experts in ultrafast spectroscopy, were skeptical. "In such organic blends, the interface morphology between polymer and fullerene is very complex and the two moieties are not covalently bound", says Lienau, "therefore one might not expect that vibronic coherence persists even at room temperature. We therefore asked Elisa Molinari and Carlo A. Rozzi, of the Istituto Nanoscienze of CNR and the University of Modena and Reggio Emilia, for help." A series of sophisticated quantum dynamics simulations, performed by Rozzi and colleagues, provided impressive movies of the evolution of the electronic cloud and of the atomic nuclei in this system, which are responsible of the oscillations found in experiments. "Our calculations indicate", says Molinari, "that the coupling between electrons and nuclei is of crucial importance for the charge transfer efficiency. Tailoring this coupling by varying the device morphology and composition hence may be important for optimizing device efficiency".

Will the new results immediately lead to better solar cells? "Such ultrafast spectroscopic studies, and in particular their comparison with advanced theoretical modelling, provide impressive and most direct insight in the fundamental phenomena that initiate the organic photovoltaic process. They turn out to be very similar to the strategies developed by Nature in photosynthesis.", says Lienau. "Recent studies indicate that quantum coherence apparently plays an important role in that case. Our new result provide evidence for similar phenomena in functional artificial photovoltaic devices: a conceptual advancement which could be used to guide the design of future artificial light-harvesting systems in an attempt to match the yet unrivalled efficiency of natural ones . "

####

For more information, please click here

Contacts:
Maddalena Scandola

39-347-077-8836

Prof. Dr. Christoph Lienau
Carl von Ossietzky University Oldenburg
Institute of Physics
Ultrafast Nano-Optics
26129 Oldenburg, Germany
Phone: +49-441-798-3485
www.uno.uni-oldenburg.de


Prof. Dr. Elisa Molinari
Istituto Nanoscienze–Consiglio Nazionale delle Ricerche (CNR),
Centro S3
via Campi 213a
41125 Modena, Italy
Phone: +39-059-205-5628
http://www.nano.cnr.it/?mod=peo&id=174

Copyright © Istituto Nanoscienze -- CNR

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

S. M. Falke et al., Coherent ultrafast charge transfer in an organic photovoltaic blend, Science 344, 1001 (2014), doi: 10.1126/science.1249771

Related News Press

News and information

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Videos/Movies

The iron stepping stones to better wearable tech without semiconductors February 8th, 2016

Novel nanoparticle made of common mineral may help keep tumor growth at bay February 4th, 2016

New invention revolutionizes heat transport February 1st, 2016

Nano-coating makes coaxial cables lighter: Rice University scientists replace metal with carbon nanotubes for aerospace use January 28th, 2016

Discoveries

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Announcements

Graphene leans on glass to advance electronics: Scientists' use of common glass to optimize graphene's electronic properties could improve technologies from flat screens to solar cells February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Energy

Graphene leans on glass to advance electronics: Scientists' use of common glass to optimize graphene's electronic properties could improve technologies from flat screens to solar cells February 12th, 2016

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Photonics/Optics/Lasers

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Silicon chip with integrated laser: Light from a nanowire: Nanolaser for information technology February 12th, 2016

Scientists take nanoparticle snapshots February 10th, 2016

Scientists create laser-activated superconductor February 8th, 2016

Solar/Photovoltaic

Graphene leans on glass to advance electronics: Scientists' use of common glass to optimize graphene's electronic properties could improve technologies from flat screens to solar cells February 12th, 2016

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Host-guest nanowires for efficient water splitting and solar energy storage February 7th, 2016

Simplifying solar cells with a new mix of materials: Berkeley Lab-led research team creates a high-efficiency device in 7 steps January 29th, 2016

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic