Ultrafast Charge Dynamics in Dilute-Donor versus Highly Intermixed TAPC:C60 Organic Solar Cell Blends.
AuthorsMoore, Gareth John
Martinez Hardigree, Josue F
KAUST DepartmentPhysical Science and Engineering (PSE) Division
Material Science and Engineering Program
KAUST Solar Center (KSC)
Embargo End Date2021-06-23
Permanent link to this recordhttp://hdl.handle.net/10754/664005
MetadataShow full item record
AbstractElucidating the interplay between film morphology, photophysics, and device performance of bulk heterojunction (BHJ) organic photovoltaics remains challenging. Here, we use the well-defined morphology of vapor-deposited di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC):C60 blends to address charge generation and recombination by transient ultrafast spectroscopy. We gain relevant new insights to the functioning of dilute-donor (5% TAPC) fullerene-based BHJs compared to molecularly intermixed systems (50% TAPC). First, we show that intermolecular charge-transfer (CT) excitons in the C60 clusters of dilute BHJs rapidly localize to Frenkel excitons prior to dissociating at the donor:acceptor interface. Thus, both Frenkel and CT excitons generate photocurrent over the entire fullerene absorption range. Second, we selectively monitor interfacial and bulk C60 clusters via their electro-absorption, demonstrating an energetic gradient that assists free charge generation. Third, we identify a fast (<1 ns) recombination channel, whereby free electrons recombine with trapped holes on isolated TAPC molecules. This can harm the performance of dilute solar cells, unless the electrons are rapidly extracted in efficient devices.
CitationMoore, G. J., Causa’, M., Martinez Hardigree, J. F., Karuthedath, S., Ramirez, I., Jungbluth, A., … Banerji, N. (2020). Ultrafast Charge Dynamics in Dilute-Donor versus Highly Intermixed TAPC:C60 Organic Solar Cell Blends. The Journal of Physical Chemistry Letters, 5610–5617. doi:10.1021/acs.jpclett.0c01495
SponsorsN.B., G.J.M., and M.C. acknowledge the Swiss National Science Foundation (Grant 200020_184819) and the University of Bern for financial support. J.F.M.H and M.R. acknowledge funding from STFC (Grant ST/L006294/1). M.R. acknowledges funding from EPSRC (Grant EP/ L026066/1) and the European Union in FP 7 (Grant 630864). This Letter is based upon work from COST Action StableNextSol MP1307 supported by COST (European Cooperation in Science and Technology), which funded Short Term Scientific Missions (STSMs) of I.R. to TU Dresden and of J.F.M.H. to the group of N.B. I.R. and A.J. acknowledge funding from EPSRC Doctoral Training grant awards, and A.J. acknowledges a Wolfson-Marriott Scholarship from Wolfson College, Oxford. Furthermore, this publication is partially based upon work supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. OSR-2018- CARF/CCF-3079. The GIWAXS data was obtained during experiment nt13183-1 at Diamond Lightsource beamline I07. We thank Dr. Koen Vandewal, Dr. Donato Spoltore (both TU Dresden), Prof. Dieter Neher (University of Potsdam), and Prof. Martijn Kemerink (University of Heidelberg) for fruitful discussions.
PublisherAmerican Chemical Society (ACS)
- 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
- What Controls the Rate of Ultrafast Charge Transfer and Charge Separation Efficiency in Organic Photovoltaic Blends.
- Authors: Jakowetz AC, Böhm ML, Zhang J, Sadhanala A, Huettner S, Bakulin AA, Rao A, Friend RH
- Issue date: 2016 Sep 14
- Syntheses, Charge Separation, and Inverted Bulk Heterojunction Solar Cell Application of Phenothiazine-Fullerene Dyads.
- Authors: Blanco GD, Hiltunen AJ, Lim GN, KC CB, Kaunisto KM, Vuorinen TK, Nesterov VN, Lemmetyinen HJ, D'Souza F
- Issue date: 2016 Apr 6
- Ultrafast Transient Spectroscopy of Polymer/Fullerene Blends for Organic Photovoltaic Applications.
- Authors: Singh S, Vardeny ZV
- Issue date: 2013 Mar 6
- Morphology of a Bulk Heterojunction Photovoltaic Cell with Low Donor Concentration.
- Authors: Lee T, Sanzogni A, Zhangzhou N, Burn PL, Mark AE
- Issue date: 2018 Sep 26