Wide-gap non-fullerene acceptor enabling high-performance organic photovoltaic cells for indoor applications

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Organic photovoltaic cells are potential candidates to drive low power consumption off-grid electronics for indoor applications. However, their power conversion efficiency is still limited by relatively large losses in the open-circuit voltage and a non-optimal absorption spectrum for indoor illumination. Here, we carefully designed a non-fullerene acceptor named IO-4Cl and blend it with a polymer donor named PBDB-TF to obtain a photoactive layer whose absorption spectrum matches that of indoor light sources. The photovoltaic characterizations reveal a low energy loss below 0.60 eV. As a result, the organic photovoltaic cell (1 cm2) shows a power conversion efficiency of 26.1% with an open-circuit voltage of 1.10 V under a light-emitting diode illumination of 1,000 lux (2,700 K). We also fabricated a large-area cell (4 cm2) through the blade-coating method. Our cell shows an excellent stability, maintaining its initial photovoltaic performance under continuous illumination of the indoor light source for 1,000 hours.

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Fig. 1: Molecular structures and ESP distributions of the materials.
Fig. 2: Absorption spectra and energy levels of the materials and their photovoltaic performances.
Fig. 3: Energy losses of PBDB-TF:IO-4Cl-based cells.
Fig. 4: Photovoltaic performance for indoor applications.
Fig. 5: Photovoltaic performance of large-area devices.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


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The authors acknowledge financial support from National Natural Science Foundation of China (Grant nos. 51673201 and 91633301), Beijing National 434 Laboratory for Molecular Sciences (Grant no. BNLMS-CXXM-201903), Chinese Academy of Sciences (Grant no. XDB12030200), the Swedish Research Council VR (2018-06048), the Swedish Energy Agency Energimyndigheten (2016-010174) and the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant no. SFO-Mat-LiU #2009-00971). F.G. is a Wallenberg Academy Fellow and O.I. is a Wallenberg Academy Scholar.

Author information

Y.C. and J.H. designed the experiments. Y.C. synthesized the acceptor material IO-4Cl. Y.C. fabricated the solar cells and carried out the published device performance measurements. F.G. led the work at Linköping. J.B. initiated the indoor characterization, performed the first indoor device measurements and contributed to the design of the indoor measurements. Y.W. measured the FTPS-EQE and EQEEL. Y.X. performed the DFT calculations. B.G. carried out photo-CELIV (charge extraction by linearly increasing voltage) measurements. C.Y. provided atomic force microscopy images. O.I. contributed to the data interpretation. S.Z. analysed the dependence of the PCEs on Rs under the indoor and AM 1.5G conditions. Y.C., H.Y., F.G. and J.H. wrote the paper. All the authors discussed the results and commented on the manuscript.

Correspondence to Feng Gao or Jianhui Hou.

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Competing interests

J.B. and O.I. are co-founders of the company Epishine AB focused on commercializing OPV for indoor applications.

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Supplementary Information

Supplementary Figs. 1–27, Supplementary Notes 1–5, Supplementary Tables 1–4 and Supplementary refs. 1–48.

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Cui, Y., Wang, Y., Bergqvist, J. et al. Wide-gap non-fullerene acceptor enabling high-performance organic photovoltaic cells for indoor applications. Nat Energy 4, 768–775 (2019) doi:10.1038/s41560-019-0448-5

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