On-demand formation of Lewis bases for efficient and stable perovskite solar cells

Sheng Fu; Nannan Sun; Hao Chen; Cheng Liu; Xiaoming Wang; You Li; Abasi Abudulimu; Yuanze Xu; Shipathi Ramakrishnan; Chongwen Li; Yi Yang; Haoyue Wan; Zixu Huang; Yeming Xian; Yifan Yin; Tingting Zhu; Haoran Chen; Amirhossein Rahimi; Muhammad Mohsin Saeed; Yugang Zhang; Qiuming Yu; David S Ginger; Randy J Ellingson; Bin Chen; Zhaoning Song; Mercouri G Kanatzidis; Edward H Sargent; Yanfa Yan

doi:10.1038/s41565-025-01900-9

On-demand formation of Lewis bases for efficient and stable perovskite solar cells

Nat Nanotechnol. 2025 Apr 17. doi: 10.1038/s41565-025-01900-9. Online ahead of print.

Authors

Sheng Fu^#¹, Nannan Sun^#², Hao Chen^#³, Cheng Liu^#³, Xiaoming Wang², You Li², Abasi Abudulimu², Yuanze Xu⁴, Shipathi Ramakrishnan⁴, Chongwen Li³, Yi Yang³, Haoyue Wan³, Zixu Huang⁵, Yeming Xian², Yifan Yin², Tingting Zhu², Haoran Chen², Amirhossein Rahimi², Muhammad Mohsin Saeed², Yugang Zhang⁶, Qiuming Yu⁴, David S Ginger⁵, Randy J Ellingson², Bin Chen³, Zhaoning Song², Mercouri G Kanatzidis³, Edward H Sargent^{7

8}, Yanfa Yan⁹

Affiliations

¹ Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, OH, USA. sheng.fu2@utoledo.edu.
² Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, OH, USA.
³ Department of Chemistry, Northwestern University, Evanston, IL, USA.
⁴ Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, USA.
⁵ Department of Chemistry, University of Washington, Seattle, WA, USA.
⁶ Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA.
⁷ Department of Chemistry, Northwestern University, Evanston, IL, USA. ted.sargent@northwestern.edu.
⁸ Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, USA. ted.sargent@northwestern.edu.
⁹ Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, OH, USA. yanfa.yan@utoledo.edu.

^# Contributed equally.

PMID: 40247140
DOI: 10.1038/s41565-025-01900-9

Abstract

In the fabrication of FAPbI₃-based perovskite solar cells, Lewis bases play a crucial role in facilitating the formation of the desired photovoltaic α-phase. However, an inherent contradiction exists in their role: they must strongly bind to stabilize the intermediate δ-phase, yet weakly bind for rapid removal to enable phase transition and grain growth. To resolve this conflict, we introduced an on-demand Lewis base molecule formation strategy. This approach utilized Lewis-acid-containing organic salts as synthesis additives, which deprotonated to generate Lewis bases precisely when needed and could be reprotonated back to salts for rapid removal once their role is fulfilled. This method promoted the optimal crystallization of α-phase FAPbI₃ perovskite films, ensuring the uniform vertical distribution of A-site cations, larger grain sizes and fewer voids at buried interfaces. Perovskite solar cells incorporating semicarbazide hydrochloride achieved an efficiency of 26.1%, with a National Renewable Energy Laboratory-certified quasi-steady-state efficiency of 25.33%. These cells retained 96% of their initial efficiency after 1,000 h of operation at 85 °C under maximum power point tracking. Additionally, mini-modules with an aperture area of 11.52 cm² reached an efficiency of 21.47%. This strategy is broadly applicable to all Lewis-acid-containing organic salts with low acid dissociation constants and offers a universal approach to enhance the performance of perovskite solar cells and modules.

Abstract

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