Abstract
Lightweight flexible perovskite solar cells are promising for building integrated photovoltaics, wearable electronics, portable energy systems and aerospace applications. However, their highest certified efficiency of 19.9% lags behind their rigid counterparts (highest 25.7%), mainly due to defective interfaces at charge-selective contacts with perovskites on top. Here we use a mixture of two hole-selective molecules based on carbazole cores and phosphonic acid anchoring groups to form a self-assembled monolayer and bridge perovskite with a low temperature-processed NiO nanocrystal film. The hole-selective contact mitigates interfacial recombination and facilitates hole extraction. We show flexible all-perovskite tandem solar cells with an efficiency of 24.7% (certified 24.4%), outperforming all types of flexible thin-film solar cell. We also report 23.5% efficiency for larger device areas of 1.05 cm2. The molecule-bridged interfaces enable significant bending durability of flexible all-perovskite tandem solar cells that retain their initial performance after 10,000 cycles of bending at a radius of 15 mm.
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The main data supporting the findings of this study are available within the published article and its Supplementary Information and source data files. Additional data are available from the corresponding author on reasonable request. Source data are provided with this paper.
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Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (61974063, U21A2076, 61904109, 62125402), Natural Science Foundation of Jiangsu Province (BK20202008, BK20190315), Fundamental Research Funds for the Central Universities (0213/14380206; 0205/14380252), the Technology Innovation Fund of Nanjing University, Frontiers Science Center for Critical Earth Material Cycling Fund (DLTD2109), the Program A for Outstanding PhD Candidate of Nanjing University and Program for Innovative Talents and Entrepreneur in Jiangsu. Calculations were performed in part at the high-performance computing centre of Jilin University. We thank W. Cai and L. Zhou from Horiba for their help on TRPL measurements.
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Contributions
H.T. conceived and directed the overall project. H.T. and L.Z. supervised the work. L.L., Y. Wang and R.L. fabricated all the devices and conducted the characterization. X.L., Z.L., K.X., Z.Z., Y. Wu and M.I.S. helped with the device fabrication and material characterization. X.W., K.Z. and L.Z. carried out the density functional theory and finite element simulations. S.X. and Q.B. performed the UPS measurements. G.C. and Z.L. performed the GIWAXS measurements. Y.T. and L.L. performed the steady-state and transient PL measurements, respectively. Y.D. carried out the SEM measurements. L.L. and J.W. performed the PLQY measurements. H.L. and C.-Q.M. performed the SFG spectrum. L.L., L.Z. and H.T. wrote the manuscript. All authors read and commented on the manuscript.
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Nature Energy thanks Fan Fu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Supplementary information
Supplementary Information
Supplementary Figs. 1–47, Notes 1–6, Tables 1–7 and References 1–45.
Supplementary Data 1
PV parameters of flexible WBG PSCs shown in Supplementary Fig. 9.
Supplementary Data 2
PV parameters of rigid WBG PSCs shown in Supplementary Fig. 15.
Supplementary Data 3
Grain size measurements of perovskite films shown in Supplementary Fig. 20c,d.
Supplementary Data 4
The individual values of the PLQY, QFLS and Voc-imp non-radiative recombination loss of the MB-NiO/perovskite junctions used in Supplementary Table 4.
Supplementary Data 5
The individual values of the PLQY and QFLS of the HTL/perovskite/C60 junctions used in Supplementary Table 5.
Supplementary Data 6
The individual values of the PLQY, QFLS and Voc-imp non-radiative recombination loss of different perovskite junctions used in Table 1.
Source data
Source Data Fig. 1
PV parameters of flexible WBG PSCs shown in Fig. 1c.
Source Data Fig. 4
PV parameters of flexible all-perovskite tandem solar cells shown in the Fig. 4e inset.
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Li, L., Wang, Y., Wang, X. et al. Flexible all-perovskite tandem solar cells approaching 25% efficiency with molecule-bridged hole-selective contact. Nat Energy 7, 708–717 (2022). https://doi.org/10.1038/s41560-022-01045-2
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DOI: https://doi.org/10.1038/s41560-022-01045-2
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