Femtosecond spectroscopic studies of photoinduced electron transfer in MDMO-PPV:ZnO hybrid bulk heterojunctions
Articolo
Data di Pubblicazione:
2007
Citazione:
Femtosecond spectroscopic studies of photoinduced electron transfer in MDMO-PPV:ZnO hybrid bulk heterojunctions / E. Cecchetto, L.H. Slooff, L. de Cola, H. Zhang. - In: JOURNAL OF LUMINESCENCE. - ISSN 0022-2313. - 122-123:1-2(2007), pp. 546-548. ((Intervento presentato al convegno International Conference on Luminescence and Optical Spectroscopy of Condensed Matter tenutosi a Beijing nel 2006 [10.1016/j.jlumin.2006.01.189].
Abstract:
The photophysics of charge carriers (polaron) in MDMO-PPV:ZnO hybrid bulk heterojunction is studied at 80 K 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 (<100 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.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
ultrafast dynamics; photophysics of polymers; spectroscopy; excited state dynamics of molecules; electron transfer
Elenco autori:
E. Cecchetto, L.H. Slooff, L. de Cola, H. Zhang
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