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Nature Energy (2026)
Moisture reactivity of metal halide perovskites remains a barrier to commercializing perovskite solar cells because it necessitates encapsulation and increases manufacturing complexity and cost. Hybrid perovskite/organic architectures that incorporate organic semiconductor layers offer a promising solution to improve moisture resistance while enhancing near-infrared photon harvesting. However, direct integration often causes energy-level misalignment and charge accumulation, limiting efficiency and stability. Here we investigate charge accumulation mechanisms and engineer the electronic structure of these hybrid solar cells using multiphysics modelling. We present a cascade hole-transfer strategy that employs an electron-donating polymer with a deep highest-occupied molecular orbital, which suppresses charge recombination in the perovskite bulk and at interfaces. Solar cells achieve a power conversion efficiency of 27.18% (certified 26.71%) and maintain 95% of their initial efficiency after 3,000 h under damp-heat conditions (ISOS D-3 protocol, 85 °C, 85% RH).
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This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2022M3H4A1A03076626, RS-2024-00449449, RS-2023-00257666 and RS-2023-00208484) and the InnoCORE programme of the Ministry of Science and ICT (1.260007.01). Computational resources were provided by KISTI (KSC-2023-CRE-0495) and UNIST-HPC.
School of Electrical Engineering (EE), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
Min-Ho Lee, Min Seok Kim, Seo-Joon Hong, Jihyung Lee & Jung-Yong Lee
UNIST InnoCORE AI-Space Solar Initiative, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
Min-Ho Lee
Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
Junho Park & Fabian Rotermund
Division of Physical Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon, Republic of Korea
Junho Park
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
Yumi Cho
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
Nayoon Kwon & Jangwon Seo
Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
Taeyoon Ki & Kwanghee Lee
School of Electrical and Electronic Engineering, University of Ulsan, Ulsan, Republic of Korea
Byeongsu Kim
Department of Chemical and Biological Engineering, Korea University, Seoul, Republic of Korea
Sang Kyu Kwak
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M.-H.L., M.S.K. and J.P. contributed equally to this work. M.-H.L., M.S.K. and J.-Y.L. conceived the idea, designed the experiments and prepared the paper. Y.C. and S.K.K. performed coarse-grained molecular dynamics (CGMD) and functional theory (DFT) analyses. J.P. and F.R. performed the transient absorption spectroscopy analyses. B.K. performed multiphysics simulations. S.-J.H., T.K. and K.L. performed the optimization of the perovskite and BHJ layers. J.L. performed atomic force microscope analysis. N.K. and J.S. performed device stability verification and analysis following the ISOS-D3 protocol. All authors discussed the results and commented on the paper.
Correspondence to Sang Kyu Kwak, Fabian Rotermund or Jung-Yong Lee.
The authors declare no competing interests.
Nature Energy thanks Yongsheng Liu, Tonghui Wang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Notes 1–7, Figs. 1–53 and Tables 1–26.
Supplementary video demonstrates the immersion test comparing water resistance of bare perovskite and hybrid perovskite/BHJ films in Fig. 4e.
Supplementary video demonstrates the washing test comparing water resistance of bare perovskite and hybrid perovskite/BHJ films in Fig. 4e.
Source data corresponding to the current density–voltage (J–V) characteristics in Fig. 1c.
Source data corresponding to the TA spectra, GSB signal and bias-dependent PL intensity in Fig. 2c,d and Fig. 2f–h.
Source data corresponding to the current density–voltage (J–V) characteristics, external quantum efficiency spectra, calculated JSC and calculated absorption plots in Fig. 3a–c, and J–V characteristics of individual devices used for the statistical source data in Fig. 3d.
Source data corresponding to the adsorption energy and adsorption distance plots in Fig. 4b. Source data for the damp-heat stability test in Fig. 4c, including the J–V characteristics of the devices. Source data for the MPP tracking in Fig. 4d, including the current density and applied voltage as a function of time. Source data for the efficiency–stability comparison of recent PSCs in Fig. 4f.
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Lee, MH., Kim, M.S., Park, J. et al. Hole-transfer cascade-engineered donor polymer for unencapsulated perovskite solar cells with improved moisture stability. Nat Energy (2026). https://doi.org/10.1038/s41560-026-02071-0
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