Title:
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Femtosecond spectroscopic studies of photoinduced electron transfer in MDMO-PPV:ZnO hybrid bulk heterojunctions
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Author(s):
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Cecchetto, E.; Slooff, L.H.; Cola, L. de; Zhang, H.
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Published by:
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Publication date:
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ECN
Solar Energy
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3-1-2007
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ECN report number:
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Document type:
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ECN-W--07-001
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Article (scientific)
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Number of pages:
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3
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Published in: Journal of Luminescence (Elsevier), , 2007, Vol.122-123, p.546-548.
Abstract:
The photophysics of charge carriers (polaron) in MDMO–PPV:ZnO hybrid bulk heterojunction is studied at 80K by femtosecond transient absorption spectroscopy. A short-lived positive polaron is observed in the blend phase in MDMO–PPV:ZnO blend films with a weight ratio of 1:1 and 1:2. Further increase of ZnO weight ratio results in a significant quenching of the polaron absorption. The results are discussed in the concept that both pristine polymer and MDMO–PPV:ZnO blend phases coexist in the blend films. It is concluded that a polaron is photogenerated within the excitation laser pulse (o100 fs) and electron transfer efficiency is highest in blend films 1:1 and 1:2. Lack of the interfacial area and faster back electron transfer process are discussed to be responsible for the quenching of the
electron transfer efficiency in blend film 1:3.
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