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An Alkylated Indacenodithieno[3,2‐ b ]thiophene‐Based Nonfullerene Acceptor with High Crystallinity Exhibiting Single Junction Solar Cell Efficiencies Greater than 13% with Low Voltage Losses
Author(s) -
Fei Zhuping,
Eisner Flurin D.,
Jiao Xuechen,
Azzouzi Mohammed,
Röhr Jason A.,
Han Yang,
Shahid Munazza,
Chesman Anthony S. R.,
Easton Christopher D.,
McNeill Christopher R.,
Anthopoulos Thomas D.,
Nelson Jenny,
Heeney Martin
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201705209
Subject(s) - materials science , thiophene , acceptor , energy conversion efficiency , side chain , polymer solar cell , crystallinity , open circuit voltage , band gap , photochemistry , polymer , optoelectronics , voltage , organic chemistry , chemistry , physics , quantum mechanics , composite material , condensed matter physics
A new synthetic route, to prepare an alkylated indacenodithieno[3,2‐ b ]thiophene‐based nonfullerene acceptor (C8‐ITIC), is reported. Compared to the reported ITIC with phenylalkyl side chains, the new acceptor C8‐ITIC exhibits a reduction in the optical band gap, higher absorptivity, and an increased propensity to crystallize. Accordingly, blends with the donor polymer PBDB‐T exhibit a power conversion efficiency (PCE) up to 12.4%. Further improvements in efficiency are found upon backbone fluorination of the donor polymer to afford the novel material PFBDB‐T. The resulting blend with C8‐ITIC shows an impressive PCE up to 13.2% as a result of the higher open‐circuit voltage. Electroluminescence studies demonstrate that backbone fluorination reduces the energy loss of the blends, with PFBDB‐T/C8‐ITIC‐based cells exhibiting a small energy loss of 0.6 eV combined with a high J SC of 19.6 mA cm −2 .