TY - JOUR
T1 - Role of nonfullerene acceptor impurities and purification on the efficiency and stability of organic photovoltaics
AU - Kumari, Tanya
AU - Ahmadpour, Mehrad
AU - Morin, Pierre Olivier
AU - Ahmad, Mariam
AU - Atajanov, Rovshen
AU - Rindom, Cecilie
AU - Oh, Jiyeon
AU - Yakoob, Mohammed Amir
AU - Bergeron, Jean Sébastien
AU - Grenier, François
AU - Yang, Changduk
AU - Nielsen, Mogens Brøndsted
AU - Turkovic, Vida
AU - Madsen, Morten
N1 - Publisher Copyright:
© 2023 The Authors. Solar RRL published by Wiley-VCH GmbH.
PY - 2023/5
Y1 - 2023/5
N2 - The introduction of nonfullerene acceptors (NFAs) has pushed the power conversion efficiency and organic photovoltaics (OPV) device stability to new standards. In this aspect, removal of trace impurities from one purification stage to the next is frequently stressed throughout the synthesis of photoactive OPV materials and NFAs to obtain the highest-purity material. However, detailed studies of the effect of purification on device performance are less reported. Herein, the role of NFA trace impurities on the optoelectronic characteristics and lifetime of resulting OPV devices is studied. The optimization of PBDB-T:ITIC-X devices, with various ITIC purity levels (X), has been thoroughly studied via a combination of photophysical, chemical, morphological, electrical, and optical characterization techniques, to shine light on the role of these impurities on device performance and lifetime. The findings suggest that, even in materials with larger concentrations of trace impurities, careful tuning can produce high efficiencies. Interestingly, the less-pure materials lead to longer device lifetimes along with an enhancement in accumulative power generation by a factor 3, compared to the purest ITIC-based devices. This demonstrates that selecting a material with the highest purity may not always be the best option for NFA OPV and that any positive effects of NFA purification must be carefully considered in light of both the device efficiency and stability.
AB - The introduction of nonfullerene acceptors (NFAs) has pushed the power conversion efficiency and organic photovoltaics (OPV) device stability to new standards. In this aspect, removal of trace impurities from one purification stage to the next is frequently stressed throughout the synthesis of photoactive OPV materials and NFAs to obtain the highest-purity material. However, detailed studies of the effect of purification on device performance are less reported. Herein, the role of NFA trace impurities on the optoelectronic characteristics and lifetime of resulting OPV devices is studied. The optimization of PBDB-T:ITIC-X devices, with various ITIC purity levels (X), has been thoroughly studied via a combination of photophysical, chemical, morphological, electrical, and optical characterization techniques, to shine light on the role of these impurities on device performance and lifetime. The findings suggest that, even in materials with larger concentrations of trace impurities, careful tuning can produce high efficiencies. Interestingly, the less-pure materials lead to longer device lifetimes along with an enhancement in accumulative power generation by a factor 3, compared to the purest ITIC-based devices. This demonstrates that selecting a material with the highest purity may not always be the best option for NFA OPV and that any positive effects of NFA purification must be carefully considered in light of both the device efficiency and stability.
KW - accumulative power generation
KW - lifetime
KW - nonfullerene acceptors
KW - organic photovoltaics
KW - trace impurities
U2 - 10.1002/solr.202300047
DO - 10.1002/solr.202300047
M3 - Journal article
AN - SCOPUS:85150078623
SN - 2367-198X
VL - 7
JO - Solar RRL
JF - Solar RRL
IS - 9
M1 - 2300047
ER -