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Polycrystalline silicon tunnelling recombination layers for high-efficiency perovskite/tunnel oxide passivating contact tandem solar cells


Perovskite/silicon tandem solar cells have rapidly advanced. Whereas efforts to enhance the device efficiency have mainly focused on top sub-cell improvements, the recombination layer connecting top and bottom sub-cells is critical for further progress. Here we present a perovskite/tunnel oxide passivating contact silicon tandem cell incorporating a tunnelling recombination layer composed of a boron- and phosphorus-doped polycrystalline silicon (poly-Si) stack. The poly-Si stack shows minimal interdiffusion of dopants. The strong adsorption ability of (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl) phosphonic acid on poly-Si substrate enables efficient charge-carrier transport and extraction, particularly for the top perovskite sub-cells. The device achieves an efficiency of 29.2% (28.76% certified) and retains 85% of its initial efficiency after 500 hours of continuous maximum power point tracking. Additionally, we provide insights into the carrier transport and tunnelling mechanisms, offering guidance for the design of intermediate layers in the pursuit of high-efficiency tandem solar cells.

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Fig. 1: Microscopic and photovoltaic properties.
Fig. 2: Characteristics and performance.
Fig. 3: MeO-2PACz adsorption calculation and characteristics.
Fig. 4: Electrical characteristics of samples on IZO and poly-Si(p+) substrates.
Fig. 5: Carrier transport mechanisms.

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All data generated or analysed during this study are included in the published article and its Supplementary Information. Any additional information is available from corresponding authors upon request. Source data are provided with this paper.


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X.L. acknowledges financial support from the National Key Research and Development of China (grant number 2022YFB4200901). J.Y. acknowledges financial support from the Zhejiang Energy Group (project number znkj-2018-118) and Ningbo ‘Innovation 2025’ Major Project (2020Z098, 2022Z114). Z. Yang acknowledges financial support from the National Natural Science Foundation of China (62004199). Y.Z. acknowledges financial support from the Key Research and Development Program of Zhejiang Province (2021C01006) and Youth Innovation Promotion Association (2018333).

Author information

Authors and Affiliations



J.Z. fabricated the TOPCon bottom cells and interlayers, did most of the measurements and wrote the first version of the paper. Z. Ying fabricated the perovskite top cells and tested the tandem devices. J.Z. and Z. Yang conceived the idea, designed the experiments and wrote the paper. Z.L. and Z. Yang contributed to the DFT and finite element simulation. H.W. contributed to the fabrication of the TOPCon bottom cells and relative tests. L.C. performed the TEM measurement. X.Y. contributed to the design of the structure of tandem cells. Y.Z. provided the resources for the experiments. X.L. supervised the project and revised the paper. J.Y. supervised the project and revised the paper.

Corresponding authors

Correspondence to Zhenhai Yang, Xi Yang, Xiaofeng Li or Jichun Ye.

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Nature Energy thanks Jan Christoph Goldschmidt, Robby Peibst and Arthur Weeber for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–36, Notes 1 and 2 and Tables 1–7.

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Supplementary Data

Source data for Supplementary Figs. 6 and 7.

Source data

Source Data Fig. 1

JV, EQE and statistical source data.

Source Data Fig. 2

ECV, SIMS, Suns-Voc and JV data.

Source Data Fig. 3

XPS data.

Source Data Fig. 4

PL and trPL data.

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Zheng, J., Ying, Z., Yang, Z. et al. Polycrystalline silicon tunnelling recombination layers for high-efficiency perovskite/tunnel oxide passivating contact tandem solar cells. Nat Energy 8, 1250–1261 (2023).

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