TY - JOUR
T1 - Intrinsic efficiency limits in low-bandgap non-fullerene acceptor organic solar cells
AU - Karuthedath, Safakath
AU - Gorenflot, Julien
AU - Firdaus, Yuliar
AU - Chaturvedi, Neha
AU - De Castro, Catherine S. P.
AU - Harrison, George T.
AU - Khan, Jafar Iqbal
AU - Markina, Anastasia
AU - Albalawi, Ahmed
AU - Peña, Top Archie Dela
AU - Liu, Wenlan
AU - Liang, Ru-Ze
AU - Sharma, Anirudh
AU - Paleti, Sri Harish Kumar
AU - Zhang, Weimin
AU - Lin, Yuanbao
AU - Alarousu, Erkki
AU - Anjum, Dalaver H.
AU - Beaujuge, Pierre
AU - De Wolf, Stefaan
AU - McCulloch, Iain
AU - Anthopoulos, Thomas D.
AU - Baran, Derya
AU - Andrienko, Denis
AU - Laquai, Frédéric
N1 - KAUST Repository Item: Exported on 2020-10-29
Acknowledged KAUST grant number(s): CRG, OSR-2018-CARF/CCF-3079
Acknowledgements: This publication is based on work supported by the KAUST Office of Sponsored Research (OSR) under award nos. OSR-2018-CARF/CCF-3079 and OSR-CRG2018-3746. D.A. acknowledges funding from the BMBF grant InterPhase and MESOMERIE (grant nos. FKZ 13N13661, FKZ 13N13656) and the European Union Horizon 2020 research and innovation program ‘Widening materials models’ under grant agreement no. 646259 (MOSTOPHOS). D.A. also acknowledges the KAUST PSE Division for hosting his sabbatical in the framework of the Division’s Visiting Faculty program. A.M. acknowledges funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 844655 (SMOLAC). We thank L. Sinatra of KAUST and Quantum Solutions LLC for assisting with the PLQY measurements. G.T.H acknowledges K. Graham and A. Amassian (and previous group members including M. Tietze and G.O.N. Ndjawa) for having designed and installed and worked on the IPES setup. In particular, G.T.H. acknowledges K. Graham’s kind assistance during the reconfiguration and optimization of the IPES setup, as well as U. Sharif for technical assistance.
PY - 2020/10/26
Y1 - 2020/10/26
N2 - In bulk heterojunction (BHJ) organic solar cells (OSCs) both the electron affinity (EA) and ionization energy (IE) offsets at the
donor–acceptor interface should equally control exciton dissociation. Here, we demonstrate that in low-bandgap non-fullerene
acceptor (NFA) BHJs ultrafast donor-to-acceptor energy transfer precedes hole transfer from the acceptor to the donor and
thus renders the EA offset virtually unimportant. Moreover, sizeable bulk IE offsets of about 0.5 eV are needed for efficient
charge transfer and high internal quantum efficiencies, since energy level bending at the donor–NFA interface caused by the
acceptors’ quadrupole moments prevents efficient exciton-to-charge-transfer state conversion at low IE offsets. The same
bending, however, is the origin of the barrier-less charge transfer state to free charge conversion. Our results provide a comprehensive picture of the photophysics of NFA-based blends, and show that sizeable bulk IE offsets are essential to design efficient
BHJ OSCs based on low-bandgap NFAs.
AB - In bulk heterojunction (BHJ) organic solar cells (OSCs) both the electron affinity (EA) and ionization energy (IE) offsets at the
donor–acceptor interface should equally control exciton dissociation. Here, we demonstrate that in low-bandgap non-fullerene
acceptor (NFA) BHJs ultrafast donor-to-acceptor energy transfer precedes hole transfer from the acceptor to the donor and
thus renders the EA offset virtually unimportant. Moreover, sizeable bulk IE offsets of about 0.5 eV are needed for efficient
charge transfer and high internal quantum efficiencies, since energy level bending at the donor–NFA interface caused by the
acceptors’ quadrupole moments prevents efficient exciton-to-charge-transfer state conversion at low IE offsets. The same
bending, however, is the origin of the barrier-less charge transfer state to free charge conversion. Our results provide a comprehensive picture of the photophysics of NFA-based blends, and show that sizeable bulk IE offsets are essential to design efficient
BHJ OSCs based on low-bandgap NFAs.
UR - http://hdl.handle.net/10754/665682
UR - http://www.nature.com/articles/s41563-020-00835-x
U2 - 10.1038/s41563-020-00835-x
DO - 10.1038/s41563-020-00835-x
M3 - Article
C2 - 33106652
JO - Nature Materials
JF - Nature Materials
SN - 1476-1122
ER -