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Nature Energy (2026)
The power conversion efficiency (PCE) of conventional tunnel oxide passivating contact (TOPCon) solar cells is fundamentally constrained by front-side recombination losses in both contact and non-contact regions. Here we demonstrate full-size bifacial TOPCon solar cells incorporating patterned front n-type TOPCon fingers and a full-area rear p-type TOPCon emitter, achieving a certified PCE of 26.34%. The devices exhibit excellent damp-heat stability and negligible light-induced degradation and light-and-elevated-temperature-induced degradation. These advances arise from the engineering of the front n-type TOPCon and rear bilayer p-type TOPCon contacts, enabled through controlled polycrystalline silicon crystallinity, dopant concentration, tunnel oxide properties and optimized silver paste formulation. Integrating this high-performance bifacial TOPCon bottom cell with a wide-bandgap perovskite top cell yields monolithic perovskite/TOPCon tandems with a certified PCE of 32.73% and an open-circuit voltage of 1.961 V. This work provides a scalable and industry-compatible pathway to higher-efficiency TOPCon and perovskite/TOPCon tandem photovoltaics.
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X.Y. acknowledges the financial support from the National Key R&D programme of China (number 2022YFB4200203), the National Natural Science Foundation of China (numbers 62174114 and U24A2063), the Key Project of Jiangsu Provincial Basic Research Plan (number BK20243031) and the Department of Science and Technology of Jiangsu Province (BE2022023 and BE2022027). This work was supported by the ‘Pioneer’ and ‘Leading Goose’ R&D Program of Zhejiang Province (grant number 2025C01154). L.Y. acknowledges financial support from the Postdoctoral Fellowship Program of CPSF (number GZC20252252) and the China Postdoctoral Science Foundation (number 2025M770174).
These authors contributed equally: Kun Gao, Jie Mao, Zhongshu Yang.
College of Energy, Soochow University, Suzhou, China
Kun Gao, Shibo Wang, Liu Yang, Wei Shi, Fengxian Cao, Chang Wang, Wenhao Li, Bowen Yang, Bo Gao & Xinbo Yang
Research and Development (R&D) Department, Zhejiang Jinko Solar Co. Ltd, Haining, China
Jie Mao, Jungan Wang, Peiting Zheng, Menglei Xu, Jie Yang & Xinyu Zhang
School of Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
Zhongshu Yang & Daniel Macdonald
Zhejiang Key Laboratory of Advanced Tandem Photovoltaic Technology, Jiaxing, China
Jungan Wang, Menglei Xu & Xinyu Zhang
School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou, China
Chengbao Liu
Suzhou Laboratory, Suzhou, China
Xinbo Yang & Xiaohong Zhang
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, China
Xiaohong Zhang
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X.Y. conceived the idea, designed the experiments and led the project. K.G. and J.M. fabricated the devices, performed the device characterizations and wrote the paper. Z.Y. and D.M. performed the Quokka simulations. L.Y., W.S., C.W., B.Y. and B.G. helped characterize and analyse the microstructure, optical and electrical properties of the poly-Si layer and TOPCon solar cells. P.Z., J.Y. and Xinyu Zhang helped with the TOPCon device optimization and analysis. S.W., F.C., J.W., M.X. and C.L. helped with the fabrication and characterization of the tandem devices. S.W. and W.L. performed the stability measurements of the tandem device. X.Y. and Xiaohong Zhang supervised the project. All authors contributed to the discussion of the results and revision of the manuscript.
Correspondence to Jie Yang, Xinyu Zhang, Xinbo Yang or Xiaohong Zhang.
J.M., J.W., P.Z., M.X., J.Y. and Xinyu Zhang are employees of Zhejiang Jinko Solar Co. Ltd. The remaining authors declare no competing interests.
Nature Energy thanks Pingqi Gao, Franz-Josef Haug and Armin Richter 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.
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Gao, K., Mao, J., Yang, Z. et al. Bifacial tunnel oxide passivating contacts for silicon and perovskite/silicon tandem solar cells with improved efficiency. Nat Energy (2026). https://doi.org/10.1038/s41560-026-02007-8
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