Open AccessEfficient Charge Transport Enables High Efficiency in Dilute Donor Organic Solar Cells
Author(s) -
Nannan Yao,
Jianqiu Wang,
Zeng Chen,
Qingzhen Bian,
Yuxin Xia,
Rui Zhang,
Jianqi Zhang,
Leiqiang Qin,
Haiming Zhu,
Yuan Zhang,
Fengling Zhang
Publication year - 2021
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.1c01219
Subject(s) - photovoltaic system , organic solar cell , materials science , acceptor , optoelectronics , stoichiometry , charge carrier , charge (physics) , electron transport chain , electron mobility , polymer , chemical physics , chemistry , condensed matter physics , physics , electrical engineering , composite material , biochemistry , quantum mechanics , engineering
The donor/acceptor weight ratio is crucial for photovoltaic performance of organic solar cells (OSCs). Here, we systematically investigate the photovoltaic behaviors of PM6:Y6 solar cells with different stoichiometries. It is found that the photovoltaic performance is tolerant to PM6 contents ranging from 10 to 60 wt %. Especially an impressive efficiency over 10% has been achieved in dilute donor solar cells with 10 wt % PM6 enabled by efficient charge generation, electron/hole transport, slow charge recombination, and field-insensitive extraction. This raises the question about the origin of efficient hole transport in such dilute donor structure. By investigating hole mobilities of PM6 diluted in Y6 and insulators, we find that effective hole transport pathway is mainly through PM6 phase in PM6:Y6 blends despite with low PM6 content. The results indicate that a low fraction of polymer donors combines with near-infrared nonfullerene acceptors could achieve high photovoltaic performance, which might be a candidate for semitransparent windows.