Abstract
Flexible perovskite solar cells have attracted substantial attention owing to their promises for soft and high power–weight compatibility. However, the inferior quality of the buried perovskite–substrate interface due to low interfacial adhesion and large deformation of flexible substrates have greatly limited the performance of flexible perovskite solar cells. Here we add the organic molecule entinostat into the hole extraction material poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) to enhance adhesion at the perovskite–substrate interface using the interaction of entinostat with perovskites, poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) and indium tin oxide through its multiple functional groups. In addition, entinostat reduces the density of voids at the bottom of the perovskite film owing to its capability to tune the crystallization of perovskites. We demonstrate inverted small-area flexible perovskite solar cells with a power conversion efficiency of 23.4%. Flexible perovskite minimodules with an area of 9 cm2 achieve a certified aperture efficiency of ~19.0%. The optimized unencapsulated flexible minimodule retains 84% of its initial efficiency after 5,000 bending cycles and 90% of the initial power conversion efficiency after light soaking for >750 h.
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Acknowledgements
This work was mainly supported by the Office of Naval Research under award N6833522C0122. Part of the material characterization is supported by the US Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy Technologies Office award no. DE-EE0009520. The DFT calculation is supported by the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science within the US Department of Energy. The views expressed herein do not necessarily represent the views of the US Department of Energy or the United States Government.
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J.H. and W.X. conceived the idea. W.X. conducted the device fabrication and measurement. Z.Z., B.C. and W.X. optimized the laser scribing process. Z.S. measured the FTIR. Y.X., X.W. and Y.Y. performed the DFT calculations. Y.L. and M.A.U. optimized the partial perovskite solution. H.G. carried out the partial (mini)module encapsulation and polydimethylsiloxane synthesis. C.F. and W.X. performed the time-resolved PL studies. N.L. conducted the partial SEM measurements. H.Z., W.X. and L.D. performed the XRD measurements and participated in the data analysis and discussion. W.X. and J.H. wrote the paper, and all authors reviewed the paper.
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J.H. has equity ownership in and serves on the board of directors of Perotech. Tandem PV has a license for the following technologies used or evaluated in this paper: an ink formulation for fast coating of perovskites and BHC for reducing iodine. J.H. is an inventor of the technologies and has or could receive royalties. These relationships have been disclosed to and are under management by UNC-Chapel Hill.
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Supplementary Video 1
Inward-bending movement of the flexible perovskite minimodule.
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Outward-bending movement of the flexible perovskite minimodule.
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Xu, W., Chen, B., Zhang, Z. et al. Multifunctional entinostat enhances the mechanical robustness and efficiency of flexible perovskite solar cells and minimodules. Nat. Photon. 18, 379–387 (2024). https://doi.org/10.1038/s41566-023-01373-z
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DOI: https://doi.org/10.1038/s41566-023-01373-z
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