A Medium-Bandgap Nonfullerene Acceptor Enabling Organic Photovoltaic Cells with 30% Efficiency under Indoor Artificial Light

Tao Zhang; Cunbin An; Ye Xu; Pengqing Bi; Zhihao Chen; Jingwen Wang; Ni Yang; Yi Yang; Bowei Xu; Huifeng Yao; Xiaotao Hao; Shaoqing Zhang; Jianhui Hou

doi:10.1002/adma.202207009

A Medium-Bandgap Nonfullerene Acceptor Enabling Organic Photovoltaic Cells with 30% Efficiency under Indoor Artificial Light

Adv Mater. 2022 Oct;34(43):e2207009. doi: 10.1002/adma.202207009. Epub 2022 Sep 27.

Authors

Tao Zhang^{1

2}, Cunbin An¹, Ye Xu¹, Pengqing Bi¹, Zhihao Chen³, Jingwen Wang^{1

2}, Ni Yang^{1

2}, Yi Yang^{1

2}, Bowei Xu¹, Huifeng Yao¹, Xiaotao Hao³, Shaoqing Zhang¹, Jianhui Hou^{1

2}

Affiliations

¹ State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² University of Chinese Academy of Sciences, Beijing, 100049, China.
³ School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China.

PMID: 36070897
DOI: 10.1002/adma.202207009

Abstract

The correlation between molecular structure and photovoltaic performance is lagging for constructing high-performance indoor organic photovoltaic (OPV) cells. Herein, this relationship is investigated in depth by employing two medium-bandgap nonfullerene acceptors (NFAs). The newly synthesized NFA of FTCCBr exhibits a similar bandgap and molecular energy level, but a much stronger dipole moment and larger average electrostatic potential (ESP) compared with ITCC. After blending with the polymer donor PB2, the PB2:ITCC and PB2:FTCCBr blends exhibit favorable bulk-heterojunction morphologies and the same driving force, but the PB2:FTCCBr blend exhibits a large ESP difference. In OPV cells, the PB2:ITCC-based device produces a power conversion efficiency (PCE) of 11.0%, whereas the PB2:FTCCBr-based device gives an excellent PCE of 14.8% with an open-circuit voltage (V_OC ) of 1.05 V, which is the highest value among OPV cells with V_OC values above 1.0 V. When both acceptor-based devices work under a 1000 lux of 3000 K light-emitting diode, the PB2:ITCC-based 1 cm² device yields a good PCE of 25.4%; in contrast, the PB2:FTCCBr-based 1 cm² device outputs a record PCE of 30.2%. These results suggest that a large ESP offset in photovoltaic materials is important for achieving high-performance OPV cells.

Keywords: electrostatic potential; exciton dissociation; indoor organic photovoltaic cells; medium-bandgap acceptors; power conversion efficiency.

Abstract

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