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Title: High-Voltage Photogeneration Exclusively via Aggregation-Induced Triplet States in a Heavy-Atom-Free Nonplanar Organic Semiconductor

Abstract

The electron–hole recombination kinetics of organic photovoltaics (OPVs) are known to be sensitive to the relative energies of triplet and charge-transfer (CT) states. Yet, the role of exciton spin in systems having CT states above 1.7 eV—like those in near-ultraviolet-harvesting OPVs—has largely not been investigated. Here, aggregation-induced room-temperature intersystem crossing (ISC) to facilitate exciton harvesting in OPVs having CT states as high as 2.3 eV and open-circuit voltages exceeding 1.6 V is reported. Triplet excimers from energy-band splitting result in ultrafast CT and charge separation with nonradiative energy losses of <250 meV, suggesting that a 0.1 eV driving force is sufficient for charge separation, with entropic gain via CT state delocalization being the main driver for exciton dissociation and generation of free charges. This finding can inform engineering of next-generation active materials and films for near-ultraviolet OPVs with open-circuit voltages exceeding 2 V. Contrary to general belief, this work reveals that exclusive and efficient ISC need not require heavy-atom-containing active materials. Molecular aggregation through thin-film processing provides an alternative route to accessing 100% triplet states on photoexcitation.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [1];  [1]; ORCiD logo [2]
  1. Princeton Univ., NJ (United States)
  2. Princeton Univ., NJ (United States). Andlinger Center for Energy and the Environment
Publication Date:
Research Org.:
Princeton Univ., NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; National Science Foundation (NSF); Swiss National Science Foundation (SNSF)
OSTI Identifier:
1595395
Alternate Identifier(s):
OSTI ID: 1574557
Grant/Contract Number:  
SC0012458; SC0015429; SC0011979; DGE-1148900; DMREF-1627453; DMR-1506097
Resource Type:
Accepted Manuscript
Journal Name:
Advanced Energy Materials
Additional Journal Information:
Journal Volume: 9; Journal Issue: 48; Journal ID: ISSN 1614-6832
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; Organic electronics; luminescence; electro-optical materials; photovoltaic devices; solar cells; intersystem crossing; triplet excitons

Citation Formats

Davy, Nicholas C., Koch, Marius, Ngongang Ndjawa, Guy Olivier, Lin, Xin, Man, Gabriel J., Lin, YunHui L., Sorli, Jeni C., Rand, Barry P., Kahn, Antoine, Scholes, Gregory D., and Loo, Yueh‐Lin. High-Voltage Photogeneration Exclusively via Aggregation-Induced Triplet States in a Heavy-Atom-Free Nonplanar Organic Semiconductor. United States: N. p., 2019. Web. doi:10.1002/aenm.201901649.
Davy, Nicholas C., Koch, Marius, Ngongang Ndjawa, Guy Olivier, Lin, Xin, Man, Gabriel J., Lin, YunHui L., Sorli, Jeni C., Rand, Barry P., Kahn, Antoine, Scholes, Gregory D., & Loo, Yueh‐Lin. High-Voltage Photogeneration Exclusively via Aggregation-Induced Triplet States in a Heavy-Atom-Free Nonplanar Organic Semiconductor. United States. doi:10.1002/aenm.201901649.
Davy, Nicholas C., Koch, Marius, Ngongang Ndjawa, Guy Olivier, Lin, Xin, Man, Gabriel J., Lin, YunHui L., Sorli, Jeni C., Rand, Barry P., Kahn, Antoine, Scholes, Gregory D., and Loo, Yueh‐Lin. Tue . "High-Voltage Photogeneration Exclusively via Aggregation-Induced Triplet States in a Heavy-Atom-Free Nonplanar Organic Semiconductor". United States. doi:10.1002/aenm.201901649.
@article{osti_1595395,
title = {High-Voltage Photogeneration Exclusively via Aggregation-Induced Triplet States in a Heavy-Atom-Free Nonplanar Organic Semiconductor},
author = {Davy, Nicholas C. and Koch, Marius and Ngongang Ndjawa, Guy Olivier and Lin, Xin and Man, Gabriel J. and Lin, YunHui L. and Sorli, Jeni C. and Rand, Barry P. and Kahn, Antoine and Scholes, Gregory D. and Loo, Yueh‐Lin},
abstractNote = {The electron–hole recombination kinetics of organic photovoltaics (OPVs) are known to be sensitive to the relative energies of triplet and charge-transfer (CT) states. Yet, the role of exciton spin in systems having CT states above 1.7 eV—like those in near-ultraviolet-harvesting OPVs—has largely not been investigated. Here, aggregation-induced room-temperature intersystem crossing (ISC) to facilitate exciton harvesting in OPVs having CT states as high as 2.3 eV and open-circuit voltages exceeding 1.6 V is reported. Triplet excimers from energy-band splitting result in ultrafast CT and charge separation with nonradiative energy losses of <250 meV, suggesting that a 0.1 eV driving force is sufficient for charge separation, with entropic gain via CT state delocalization being the main driver for exciton dissociation and generation of free charges. This finding can inform engineering of next-generation active materials and films for near-ultraviolet OPVs with open-circuit voltages exceeding 2 V. Contrary to general belief, this work reveals that exclusive and efficient ISC need not require heavy-atom-containing active materials. Molecular aggregation through thin-film processing provides an alternative route to accessing 100% triplet states on photoexcitation.},
doi = {10.1002/aenm.201901649},
journal = {Advanced Energy Materials},
number = 48,
volume = 9,
place = {United States},
year = {2019},
month = {11}
}

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Works referenced in this record:

Charge Generation and Recombination in an Organic Solar Cell with Low Energetic Offsets
journal, October 2017

  • Ran, Niva A.; Love, John A.; Heiber, Michael C.
  • Advanced Energy Materials, Vol. 8, Issue 5
  • DOI: 10.1002/aenm.201701073

Contorted Hexabenzocoronenes with Extended Heterocyclic Moieties Improve Visible-Light Absorption and Performance in Organic Solar Cells
journal, January 2016


Open circuit voltage of organic solar cells: an in-depth review
journal, January 2016

  • Elumalai, Naveen Kumar; Uddin, Ashraf
  • Energy & Environmental Science, Vol. 9, Issue 2
  • DOI: 10.1039/C5EE02871J

Intrinsic non-radiative voltage losses in fullerene-based organic solar cells
journal, April 2017

  • Benduhn, Johannes; Tvingstedt, Kristofer; Piersimoni, Fortunato
  • Nature Energy, Vol. 2, Issue 6
  • DOI: 10.1038/nenergy.2017.53

The role of spin in the kinetic control of recombination in organic photovoltaics
journal, August 2013

  • Rao, Akshay; Chow, Philip C. Y.; Gélinas, Simon
  • Nature, Vol. 500, Issue 7463
  • DOI: 10.1038/nature12339

Elektronenübertragungsreaktionen des angeregten Perylens
journal, October 1963

  • Leonhardt, Horst; Weller, Albert
  • Berichte der Bunsengesellschaft für physikalische Chemie, Vol. 67, Issue 8
  • DOI: 10.1002/bbpc.19630670810

Bildung von Molekülkomplexen im angeregten Zustand mit kurzwellig absorbierenden Aromaten
journal, September 1967


On the origin of the open-circuit voltage of polymer–fullerene solar cells
journal, October 2009

  • Vandewal, Koen; Tvingstedt, Kristofer; Gadisa, Abay
  • Nature Materials, Vol. 8, Issue 11, p. 904-909
  • DOI: 10.1038/nmat2548

External Quantum Efficiency Above 100% in a Singlet-Exciton-Fission-Based Organic Photovoltaic Cell
journal, April 2013


Electron-hole interaction energy in the organic molecular semiconductor PTCDA
journal, June 1997


Morphological Tuning of the Energetics in Singlet Fission Organic Solar Cells
journal, July 2016

  • Lin, YunHui L.; Fusella, Michael A.; Kozlov, Oleg V.
  • Advanced Functional Materials, Vol. 26, Issue 35
  • DOI: 10.1002/adfm.201601125

Local Intermolecular Order Controls Photoinduced Charge Separation at Donor/Acceptor Interfaces in Organic Semiconductors
journal, January 2016

  • Feier, Hilary M.; Reid, Obadiah G.; Pace, Natalie A.
  • Advanced Energy Materials, Vol. 6, Issue 6
  • DOI: 10.1002/aenm.201502176

Rational Molecular Design for Achieving Persistent and Efficient Pure Organic Room-Temperature Phosphorescence
journal, October 2016


Room temperature triplet state spectroscopy of organic semiconductors
journal, January 2014

  • Reineke, Sebastian; Baldo, Marc A.
  • Scientific Reports, Vol. 4, Issue 1
  • DOI: 10.1038/srep03797

ImageJ2: ImageJ for the next generation of scientific image data
journal, November 2017

  • Rueden, Curtis T.; Schindelin, Johannes; Hiner, Mark C.
  • BMC Bioinformatics, Vol. 18, Issue 1
  • DOI: 10.1186/s12859-017-1934-z

Mechanism of Quenching of Triplet States by Molecular Oxygen:  Biphenyl Derivatives in Different Solvents
journal, July 1999

  • Wilkinson, Francis; Abdel-Shafi, Ayman A.
  • The Journal of Physical Chemistry A, Vol. 103, Issue 28
  • DOI: 10.1021/jp9907995

Singlet Fission in Rubrene Derivatives: Impact of Molecular Packing
journal, March 2017


Direct Observation of Ultrafast Excimer Formation in Covalent Perylenediimide Dimers Using Near-Infrared Transient Absorption Spectroscopy
journal, July 2014

  • Brown, Kristen E.; Salamant, Walter A.; Shoer, Leah E.
  • The Journal of Physical Chemistry Letters, Vol. 5, Issue 15
  • DOI: 10.1021/jz5011797

Polymer Triplet Energy Levels Need Not Limit Photocurrent Collection in Organic Solar Cells
journal, November 2012

  • Schlenker, Cody W.; Chen, Kung-Shih; Yip, Hin-Lap
  • Journal of the American Chemical Society, Vol. 134, Issue 48
  • DOI: 10.1021/ja306110b

Tuning kinetic competitions to traverse the rich structural space of organic semiconductor thin films
journal, July 2015

  • Hiszpanski, Anna M.; Khlyabich, Petr P.; Loo, Yueh-Lin
  • MRS Communications, Vol. 5, Issue 3
  • DOI: 10.1557/mrc.2015.55

Charge Recombination in Organic Photovoltaic Devices with High Open-Circuit Voltages
journal, October 2008

  • Westenhoff, Sebastian; Howard, Ian A.; Hodgkiss, Justin M.
  • Journal of the American Chemical Society, Vol. 130, Issue 41
  • DOI: 10.1021/ja803054g

Halogenation of a Nonplanar Molecular Semiconductor to Tune Energy Levels and Bandgaps for Electron Transport
journal, February 2015


Recombination in Polymer:Fullerene Solar Cells with Open-Circuit Voltages Approaching and Exceeding 1.0 V
journal, September 2012

  • Hoke, Eric T.; Vandewal, Koen; Bartelt, Jonathan A.
  • Advanced Energy Materials, Vol. 3, Issue 2
  • DOI: 10.1002/aenm.201200474

What Controls the Rate of Ultrafast Charge Transfer and Charge Separation Efficiency in Organic Photovoltaic Blends
journal, September 2016

  • Jakowetz, Andreas C.; Böhm, Marcus L.; Zhang, Jiangbin
  • Journal of the American Chemical Society, Vol. 138, Issue 36
  • DOI: 10.1021/jacs.6b05131

Excimer formation in pyrene molecular crystal: Femtosecond dynamics of an oriented bimolecular reaction
journal, December 1987

  • Williams, Leah Ruby; Nelson, Keith A.
  • The Journal of Chemical Physics, Vol. 87, Issue 12
  • DOI: 10.1063/1.453331

Observation of long-range exciton diffusion in highly ordered organic semiconductors
journal, October 2010

  • Najafov, H.; Lee, B.; Zhou, Q.
  • Nature Materials, Vol. 9, Issue 11
  • DOI: 10.1038/nmat2872

Post-deposition Processing Methods To Induce Preferential Orientation in Contorted Hexabenzocoronene Thin Films
journal, December 2012

  • Hiszpanski, Anna M.; Lee, Stephanie S.; Wang, He
  • ACS Nano, Vol. 7, Issue 1
  • DOI: 10.1021/nn304003u

The Energy of Charge‐Transfer States in Electron Donor–Acceptor Blends: Insight into the Energy Losses in Organic Solar Cells
journal, June 2009

  • Veldman, Dirk; Meskers, Stefan C. J.; Janssen, René A. J.
  • Advanced Functional Materials, Vol. 19, Issue 12
  • DOI: 10.1002/adfm.200900090

Energy Transfer Mechanisms and the Molecular Exciton Model for Molecular Aggregates
journal, September 1963


Charge Localization after Ultrafast Photoexcitation of a Rigid Perylene Perylenediimide Dyad Visualized by Transient Stark Effect
journal, April 2017

  • Koch, Marius; Myahkostupov, Mykhaylo; Oblinsky, Daniel G.
  • Journal of the American Chemical Society, Vol. 139, Issue 15
  • DOI: 10.1021/jacs.7b01630

Triplet Exciton Generation in Bulk-Heterojunction Solar Cells Based on Endohedral Fullerenes
journal, June 2011

  • Liedtke, Moritz; Sperlich, Andreas; Kraus, Hannes
  • Journal of the American Chemical Society, Vol. 133, Issue 23
  • DOI: 10.1021/ja2025432

Exciplex Formation in Bimolecular Photoinduced Electron-Transfer Investigated by Ultrafast Time-Resolved Infrared Spectroscopy
journal, February 2014

  • Koch, Marius; Letrun, Romain; Vauthey, Eric
  • Journal of the American Chemical Society, Vol. 136, Issue 10
  • DOI: 10.1021/ja500812u

Dielectric Effect on the Photovoltage Loss in Organic Photovoltaic Cells
journal, July 2014

  • Chen, Song; Tsang, Sai-Wing; Lai, Tzung-Han
  • Advanced Materials, Vol. 26, Issue 35
  • DOI: 10.1002/adma.201401987

Competition between the Charge Transfer State and the Singlet States of Donor or Acceptor Limiting the Efficiency in Polymer:Fullerene Solar Cells
journal, December 2011

  • Faist, Mark A.; Kirchartz, Thomas; Gong, Wei
  • Journal of the American Chemical Society, Vol. 134, Issue 1
  • DOI: 10.1021/ja210029w

Pairing of near-ultraviolet solar cells with electrochromic windows for smart management of the solar spectrum
journal, June 2017


Offset energies at organic semiconductor heterojunctions and their influence on the open-circuit voltage of thin-film solar cells
journal, March 2007


Access to Triplet Excited State in Core-Twisted Perylenediimide
journal, April 2016

  • Nagarajan, Kalaivanan; Mallia, Ajith R.; Reddy, V. Sivaranjana
  • The Journal of Physical Chemistry C, Vol. 120, Issue 16
  • DOI: 10.1021/acs.jpcc.6b00755

Direct Observation of Excimer-Mediated Intramolecular Electron Transfer in a Cofacially-Stacked Perylene Bisimide Pair
journal, July 2016

  • Sung, Jooyoung; Nowak-Król, Agnieszka; Schlosser, Felix
  • Journal of the American Chemical Society, Vol. 138, Issue 29
  • DOI: 10.1021/jacs.6b04591

Triplet states in organic semiconductors
journal, November 2009


Singlet exciton fission in solution
journal, November 2013

  • Walker, Brian J.; Musser, Andrew J.; Beljonne, David
  • Nature Chemistry, Vol. 5, Issue 12
  • DOI: 10.1038/nchem.1801

The exciton model in molecular spectroscopy
journal, January 1965

  • Kasha, M.; Rawls, H. R.; Ashraf El-Bayoumi, M.
  • Pure and Applied Chemistry, Vol. 11, Issue 3-4
  • DOI: 10.1351/pac196511030371

Triplet Excimer Emission in a Series of 4,4′-Bis( N -carbazolyl)-2,2′-biphenyl Derivatives
journal, January 2011

  • Hoffmann, S. T.; Schrögel, P.; Rothmann, M.
  • The Journal of Physical Chemistry B, Vol. 115, Issue 3
  • DOI: 10.1021/jp107408e