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Managing grains and interfaces via ligand anchoring enables 22.3%-efficiency inverted perovskite solar cells


Inverted perovskite solar cells have attracted increasing attention because they have achieved long operating lifetimes. However, they have exhibited significantly inferior power conversion efficiencies compared to regular perovskite solar cells. Here we reduce this efficiency gap using a trace amount of surface-anchoring alkylamine ligands (AALs) with different chain lengths as grain and interface modifiers. We show that long-chain AALs added to the precursor solution suppress nonradiative carrier recombination and improve the optoelectronic properties of mixed-cation mixed-halide perovskite films. The resulting AAL surface-modified films exhibit a prominent (100) orientation and lower trap-state density as well as enhanced carrier mobilities and diffusion lengths. These translate into a certified stabilized power conversion efficiency of 22.3% (23.0% power conversion efficiency for lab-measured champion devices). The devices operate for over 1,000 h at the maximum power point under simulated AM1.5 illumination, without loss of efficiency.

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Fig. 1: Optical and structural characterization of perovskite films with AALs.
Fig. 2: Device structure and PV performance analysis.
Fig. 3: Defect density and energy-level characterization of perovskite films with AALs.
Fig. 4: DFT calculation of the trap states on the surface of various crystallographic facets.
Fig. 5: Schematic illustration of the likely mechanisms underpinning efficiency enhancements.
Fig. 6: Ion migration and long-term device stability.

Data availability

The main data supporting the findings of this study are available within the article and its Supplementary Information. Additional data are available from the corresponding authors on reasonable request.


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We acknowledge the use of KAUST Core Lab and KAUST Solar Center facilities. This work was supported by KAUST and the Office of Sponsored Research (OSR) under award no. OSR-2017-CRG-3380. F.G. is a Wallenberg Academy Fellow.

Author information




O.M.B., X.Z., Y.H. and E.H.S. conceived the idea and designed the experiments. X.Z. fabricated the devices and conducted the characterizations. Y.H. contributed to device fabrication and evaluation, the MPP stability test and TRPL measurement. C.B. contributed to the measurements of thermal admittance spectroscopy, transient photo-voltage, ion migration and LEDs. J.Y. performed and interpreted the DFT calculation. J.L. performed the XRD measurements. A.K.J. performed the GIWAXS measurements. K.S., J.L., N.W., B.T. and C.Y. contributed to the electron microscopy measurements. N.G. contributed to the light-intensity-dependent JV measurements. Y.L. contributed to the atomic force microscopy and contact angle measurements. A.Y.A. contributed to the PL measurements and PL mapping. F.Y., C.Z., Z.H., P.M., D.X., B.C. and M.W. contributed to TRPL and analyses. M.N.H. performed the UPS measurements. J.T. contributed to the stability measurements. D.B., T.D.A., Y.H., Z.H.L., O.F.M., F.G. and E.H.S. provided advice and expertise. X.Z., O.M.B., Y.H. and E.H.S. composed the manuscript. All authors discussed the results and commented on the manuscript.

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Correspondence to Edward H. Sargent or Osman M. Bakr.

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Zheng, X., Hou, Y., Bao, C. et al. Managing grains and interfaces via ligand anchoring enables 22.3%-efficiency inverted perovskite solar cells. Nat Energy 5, 131–140 (2020).

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