title: Tuning the driving force for exciton dissociation in single-walled carbon nanotube heterojunctions.
abstract: Understanding the kinetics and energetics of interfacial electron transfer in molecular systems is crucial for the development of a broad array of technologies, including photovoltaics, solar fuel systems and energy storage. The Marcus formulation for electron transfer relates the thermodynamic driving force and reorganization energy for charge transfer between a given donor/acceptor pair to the kinetics and yield of electron transfer. Here we investigated the influence of the thermodynamic driving force for photoinduced electron transfer (PET) between single-walled carbon nanotubes (SWCNTs) and fullerene derivatives by employing time-resolved microwave conductivity as a sensitive probe of interfacial exciton dissociation. For the first time, we observed the Marcus inverted region (in which driving force exceeds reorganization energy) and quantified the reorganization energy for PET for a model SWCNT/acceptor system. The small reorganization energies (about 130 meV, most of which probably arises from the fullerene acceptors) are beneficial in minimizing energy loss in photoconversion schemes.
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
authors.forename: Rachelle
authors.initials: R
authors.lastname: Ihly
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.|Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Mistry
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Ferguson
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.|Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Tyler T
authors.initials: TT
authors.lastname: Clikeman
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.|Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Bryon W
authors.initials: BW
authors.lastname: Larson
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.|Department of Chemistry &Biochemistry and RASEI, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Obadiah
authors.identifier: 0000-0003-0646-3981
authors.initials: O
authors.lastname: Reid
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Boltalina
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Strauss
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.|Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.|Department of Chemistry &Biochemistry and RASEI, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Garry
authors.initials: G
authors.lastname: Rumbles
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Blackburn