Abstract
To unlock the full performance potential of silicon heterojunction solar cells requires reductions of parasitic absorption and shadowing losses. Yet the translation of the hydrogenated nanocrystalline silicon oxide (nc-SiOx:H) window layer and copper-plated electrodes to a cost-effective and scalable production-relevant context remains one of the largest roadblocks towards mainstream adoption of silicon heterojunction technology. Here we address the first challenge by developing an industrial-scale high-frequency plasma-enhanced chemical vapour deposition system with a minimized standing wave effect, enabling the deposition of doped nc-SiOx:H with excellent electron selectivity, low parasitic absorption and high uniformity. Next, we demonstrate seed-free copper plating, resulting in grids with a high aspect ratio and low metal fraction. By implementing the doped nc-SiOx:H window layer, certified efficiencies of 25.98% and 26.41% are obtained for M6-size bifacial silicon heterojunction devices with screen-printed silver electrodes and copper-plated electrodes, respectively. These results underline the performance potential of silicon heterojunction technology and lower the threshold towards their mass manufacturing.
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Acknowledgements
X.Y. acknowledges the financial support from the National Natural Science Foundation of China (no. 62174114), the National Key R&D Program of China (no. 2022YFB4200203), the Department of Science and Technology of Jiangsu Province (no. BE2022027, no. BE2022036, no. BE2022023), the Distinguished Professor Award of Jiangsu Province and the ‘Dual Carbon’ Science and Technology Project of Suzhou (no. ST202219). X.Z. acknowledges the financial support from the Major Research Plan of the National Natural Science Foundation of China (no. 91833303) and the Foundation for Innovation Research Groups of the National Natural Science Foundation of China (no. 51821002). J. Zhou acknowledges the financial support from the Carbon Emission Peak and Carbon Neutrality Special Fund of Jiangsu Province (no. BA2022205). This work is partly supported by the Australian Renewable Energy Agency (ARENA) under 2020/ARP006. The views expressed herein are not necessarily the views of the Australian Government, and the Australian Government does not accept responsibility for any information or advice contained herein. We thank X. Ran, J. Allen and S. Drury for sample preparation and device fabrication.
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X.Y. and C.Y. conceived the idea, designed the experiments and led the project. C.Y. and K.G. fabricated the devices, performed the device characterizations and wrote the paper. C.-W.P. and C.H. helped with the device optimization and analysis. S.W. and W.S. performed the Raman spectra and contact resistivity measurements. J. Zhang and D.W. performed the large-scale uniformity experiment. V.A., Y.H., J.C., Huiting Wu, L.G., D.C. and A.L. designed and carried out the copper plating. G.T., Y.Z., W.J. and Y.S. performed the simulation validation of the voltage distribution on excitation frequency and substrate size. G.D. performed the TCO deposition, and H.J. performed screen printing. Haihong Wu performed lifetime, EQE and HR-TEM measurements. C.X., Q.M. and X.W. performed HR-TEM and EQE measurements. K.L. and D.X. performed the absorption spectra and optical bandgap measurement. J.P. and W.L. helped with the TOF-SIMS result analysis and discussion. X.C. designed the PECVD chamber. S.D.W. helped with the discussion of the results. J. Zhou, X.Y. and X.Z. supervised the project. All authors contributed to the discussion of the results and revision of the manuscript.
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C.Y., C.-W.P., C.H., J. Zhou, D.W., G.T., G.D., H.J., Haihong Wu, X.C. and J. Zhang are employees of Suzhou Maxwell Technologies Co. Ltd. V.A., D.C., A.L., Y.H., J.C., Huiting Wu and L.G. are employees of SunDrive Solar Pty., Ltd. All other authors declare no competing interests.
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Certified I–V and EQE data.
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Photovoltaic parameter data.
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Raman and contact resistivity data.
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Thickness and PCE uniformity data.
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Voltage distribution simulation data.
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PCE and TOF-SIMS data.
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Certified I–V data.
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Yu, C., Gao, K., Peng, CW. et al. Industrial-scale deposition of nanocrystalline silicon oxide for 26.4%-efficient silicon heterojunction solar cells with copper electrodes. Nat Energy 8, 1375–1385 (2023). https://doi.org/10.1038/s41560-023-01388-4
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DOI: https://doi.org/10.1038/s41560-023-01388-4
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