Charge Transfer Dynamics in Polymer-Fullerene Blends for Efficient Solar Cells

Dorota Jarzab*, Fabrizio Cordella, Martijn Lenes, Floris B. Kooistra, Paul W.M. Blom, Jan C. Hummelen, Maria A. Loi

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

47 Citaten (Scopus)
316 Downloads (Pure)

Samenvatting

Blends of poly(3-hexylthiophene) (P3HT) and the bis-adduct of [6,6]-phenyl-C(61)-butyric acid methyl ester (bisPCBM) show enhanced performances in bulk-heterojunction solar cells compared to P3HT:PCBM thin films due to their higher open-circuit voltage. However, it is not clear whether the decrease of the short-circuit current observed in P3HT-bisPCBM blends originates from the 100 mV reduction of the offset between the lowest unoccupied molecular orbitals of the donor and the acceptor or from a change in the morphology. The analysis of the photoluminescence dynamics of the various bulk heterojunctions provides information on the dependence of the electron transfer process on their microstructure. We find that in solution, where the donor-acceptor distribution is homogeneous, the photoluminescence dynamics is the same for the bis- and PCBM-based blends, while in thin films the first shows it slower dynamics than the second. This result indicates that the reduction of the LUMO offset of similar to 100 meV does not influence the electron transfer efficiency but that the diversity between the photoluminescence dynamics in thin films should be ascribed to the different microstucture of the bulk heterojunctions fabricated with the two acceptors.

Originele taal-2English
Pagina's (van-tot)16513-16517
Aantal pagina's5
TijdschriftJournal of Physical Chemistry B
Volume113
Nummer van het tijdschrift52
DOI's
StatusPublished - 31-dec-2009

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