Direct correlation of charge transfer absorption with molecular donor:acceptor interfacial area via photothermal deflection spectroscopy
Watkins, Scott E.
Scholes, Fiona H.
Bannock, James H
de Mello, John
Richter, Lee J.
DeLongchamp, Dean M.
Permanent link to this recordhttp://hdl.handle.net/10754/550071
MetadataShow full item record
AbstractWe show that the Charge Transfer (CT) absorption signal in bulk-heterojunction (BHJ) solar cell blends, measured by photothermal deflection spectroscopy (PDS), is directly proportional to the density of molecular donor/acceptor interfaces. Since the optical transitions from ground state to the interfacial CT state are weakly allowed at photon energies below the optical gap of both donor and acceptor, we can exploit the use of this sensitive linear absorption spectroscopy for such quantification. Moreover, we determine the absolute molar extinction coefficient of the CT transition for an archetypical polymer-fullerene interface. The latter is ~100 times lower than the extinction coefficient of the donor chromophore involved, allowing us to experimentally estimate the transition dipole moment (0.3 D) and the electronic coupling between ground state and CT state to be on the order of 30 meV.
CitationDirect correlation of charge transfer absorption with molecular donor:acceptor interfacial area via photothermal deflection spectroscopy 2015:150409144253004 Journal of the American Chemical Society
PublisherAmerican Chemical Society (ACS)
- Revelation of Interfacial Energetics in Organic Multiheterojunctions.
- Authors: Kästner C, Vandewal K, Egbe DAM, Hoppe H
- Issue date: 2017 Apr
- Quantifying charge transfer energies at donor-acceptor interfaces in small-molecule solar cells with constrained DFTB and spectroscopic methods.
- Authors: Scholz R, Luschtinetz R, Seifert G, Jägeler-Hoheisel T, Körner C, Leo K, Rapacioli M
- Issue date: 2013 Nov 27
- Ultrafast exciton dissociation followed by nongeminate charge recombination in PCDTBT:PCBM photovoltaic blends.
- Authors: Etzold F, Howard IA, Mauer R, Meister M, Kim TD, Lee KS, Baek NS, Laquai F
- Issue date: 2011 Jun 22
- Probing charge transfer states at organic and hybrid internal interfaces by photothermal deflection spectroscopy.
- Authors: Becker-Koch D, Rivkin B, Paulus F, Xiang H, Dong Y, Chen Z, Bakulin AA, Vaynzof Y
- Issue date: 2019 Mar 27
- Charge-transfer excitons at organic semiconductor surfaces and interfaces.
- Authors: Zhu XY, Yang Q, Muntwiler M
- Issue date: 2009 Nov 17