Publication Date:
2013-04-20
Description:
Singlet exciton fission transforms a molecular singlet excited state into two triplet states, each with half the energy of the original singlet. In solar cells, it could potentially double the photocurrent from high-energy photons. We demonstrate organic solar cells that exploit singlet exciton fission in pentacene to generate more than one electron per incident photon in a portion of the visible spectrum. Using a fullerene acceptor, a poly(3-hexylthiophene) exciton confinement layer, and a conventional optical trapping scheme, we show a peak external quantum efficiency of (109 +/- 1)% at wavelength lambda = 670 nanometers for a 15-nanometer-thick pentacene film. The corresponding internal quantum efficiency is (160 +/- 10)%. Analysis of the magnetic field effect on photocurrent suggests that the triplet yield approaches 200% for pentacene films thicker than 5 nanometers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Congreve, Daniel N -- Lee, Jiye -- Thompson, Nicholas J -- Hontz, Eric -- Yost, Shane R -- Reusswig, Philip D -- Bahlke, Matthias E -- Reineke, Sebastian -- Van Voorhis, Troy -- Baldo, Marc A -- New York, N.Y. -- Science. 2013 Apr 19;340(6130):334-7. doi: 10.1126/science.1232994.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Energy Frontier Research Center for Excitonics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23599489" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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