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Phase-heterojunction all-inorganic perovskite solar cells surpassing 21.5% efficiency


Making organic–inorganic metal halide-based multijunction perovskite solar cells either by solution processes or physical techniques is not straightforward. Here we propose and developed dimethylammonium iodide-assisted β−CsPbI3 and guanidinium iodide-assisted γ−CsPbI3 all-inorganic phase-heterojunction solar cells (PHSs) by integrating hot-air and triple-source thermal evaporation deposition techniques, respectively. Incorporating a (Zn(C6F5)2) molecular additive and dopant-free hole transport layer produces a 21.59% power conversion efficiency (PCE). The laboratory-to-module scale shows 18.43% PCE with an 18.08 cm2 active area. We demonstrate that this additive-assisted β−γ-based PHS structure exhibited >200 hours of stable performance under maximum power tracking under one sun illumination. This work paves the way towards dual deposition techniques for PHS with important consequences not only for all inorganic but also for other halide perovskite compositions.

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Fig. 1: Fabrication of PHSs.
Fig. 2: β−CsPbI3 and γ−CsPbI3 interface analysis and thin film characterization.
Fig. 3: Structural, optoelectronic and photovoltaic properties.
Fig. 4: Reproducibility, dark current and photocurrent stability properties.
Fig. 5: Large-area fabrication and stability analysis.
Fig. 6: Photovoltaic performance of the β−CsPbI3-Zn(C6F5)2/γ−CsPbI3-GAI-based PSM.

Data availability

All data generated or analysed during this study are included in the published article and its Supplementary Information and Source Data files. Data used for Figs. 4a and 6e, Table 1 and Supplementary Figs. 24a, 25b and 28 are available at Source data are provided with this paper.


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This research is supported by the National Research Foundation of Korea (NRF) (2020R1A2C2004880). This work was also supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2018R1A6A1A03024334). S.R.R. acknowledges the support of the Department of Materials Engineering, Indian Institute of Science (IISc), Bengaluru, India. N.Y.D. acknowledges the support of the College of Earth and Minerals Sciences and the John and Willie Leone Family Department of Energy and Mineral Engineering of Pennsylvania State University. Computer simulations for this work were performed on the Roar Supercomputer of The Pennsylvania State University. Y.-W.Z. acknowledges the funding support of the Natural Science Foundation of Beijing Municipality (2191003). We thank G. G. Jeong for helping with GIXRD measurements, from the Chonnam Center for Research Facilities (CCRF), Chonnam National University, Gwangju, and we also thank J. A. Steele from the School of Mathematics and Physics from the University of Queensland for helping with XRD analysis.

Author information

Authors and Affiliations



S.S.M. conceived the idea, initialized the project and fabricated devices and did almost all characterizations. C.K.H. directed and supervised the project and fund acquisition. S.S.M. and J.V.P. contributed fabrication to rear γ–CsPbI3 layer fabrication and stability experimental setup and monitored stability. S.R.R. carried out interface investigation and band alignment. N.Y.D. contributed to DFT formal analysis, investigation and methodology. J.-Y.S. and Y.-W.Z. synthesized SMe-TATPyr HTL. Top γ−CsPbI3 layers were optimized by J.V.P. and S.S.M. All authors contributed to discussions and to finalizing the paper.

Corresponding authors

Correspondence to Sawanta S. Mali or Chang Kook Hong.

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Nature Energy thanks Gary Hodes, Ana Flavia Nogueira 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. 1–40, Notes 1–8, Tables 1–20 and Movies 1 and 2.

Reporting Summary

Supplementary Video 1

In-situ deposition of γ–CsPbI3-GAI-based perovskite thin film by thermal evaporation at module scale (13 cm × 13 cm = 169 cm2).

Supplementary Video 2

Captions for Supplementary Movie 2: testing of 13 × 13 cm2 PHS-based module under LED lamp in ambient conditions.

Supplementary Data

Source data file for Supplementary Fig. 24a.

Supplementary Data

Source data file for Supplementary Fig. 25b.

Supplementary Data

Source data file for Supplementary Fig. 28.

Source data

Source Data Fig. 4a

Statistical source data for Fig. 4a.

Source Data Fig. 6e

Statistical source data for Fig. 6e.

Source Data Table 1

Statistical source data for Table 1.

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Mali, S.S., Patil, J.V., Shao, JY. et al. Phase-heterojunction all-inorganic perovskite solar cells surpassing 21.5% efficiency. Nat Energy 8, 989–1001 (2023).

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