Polaron pair mediated triplet generation in polymer/fullerene blends
AuthorsDimitrov, Stoichko D.
Schroeder, Bob C.
Frost, Jarvist M.
Tuladhar, Pabitra S.
Durrant, James R.
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/346697
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AbstractElectron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whether it involves spin-state mixing is not well understood. In this work, the dynamics of free charge separation competing with recombination to polymer triplet states is studied in two closely related polymer-fullerene blends with differing polymer fluorination and photovoltaic performance. Using time-resolved laser spectroscopic techniques and quantum chemical calculations, we show that lower charge separation in the fluorinated system is associated with the formation of bound electron-hole pairs, which undergo spin-state mixing on the nanosecond timescale and subsequent geminate recombination to triplet excitons. We find that these bound electron-hole pairs can be dissociated by electric fields.
CitationPolaron pair mediated triplet generation in polymer/fullerene blends 2015, 6:6501 Nature Communications
PubMed Central IDPMC4366531
- 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
- The role of spin in the kinetic control of recombination in organic photovoltaics.
- Authors: Rao A, Chow PC, Gélinas S, Schlenker CW, Li CZ, Yip HL, Jen AK, Ginger DS, Friend RH
- Issue date: 2013 Aug 22
- The effect of solvent additives on morphology and excited-state dynamics in PCPDTBT:PCBM photovoltaic blends.
- Authors: Etzold F, Howard IA, Forler N, Cho DM, Meister M, Mangold H, Shu J, Hansen MR, Müllen K, Laquai F
- Issue date: 2012 Jun 27
- Ultrafast hole transfer mediated by polaron pairs in all-polymer photovoltaic blends.
- Authors: Wang R, Yao Y, Zhang C, Zhang Y, Bin H, Xue L, Zhang ZG, Xie X, Ma H, Wang X, Li Y, Xiao M
- Issue date: 2019 Jan 23
- Spectroscopic Investigation of the Effect of Microstructure and Energetic Offset on the Nature of Interfacial Charge Transfer States in Polymer: Fullerene Blends.
- Authors: Dimitrov SD, Azzouzi M, Wu J, Yao J, Dong Y, Tuladhar PS, Schroeder BC, Bittner ER, McCulloch I, Nelson J, Durrant JR
- Issue date: 2019 Mar 20