Perovskite–organic tandem solar cells with a photo

Abstract Wide-bandgap (WBG) mixed-halide perovskites with high Br content, which are employed as the front cell material in perovskite–organic tandem solar cells (TSCs), often suffer from initial halide-mixing inhomogeneity and light-induced halide segregation1–3, limiting the performance of perovskite–organic TSCs. Here, we introduced a photo-transformable additive 4-[3-(trifluoromethyl)-3H-diazirin-3-yl]benzylamine (TDB) into the WBG perovskite precursor solution to establish a two-stage strategy for stabilizing the mixed-halide phase. During crystallization, TDB improves the initial halide homogeneity by suppressing the rapid precipitation of the Br-rich phase and accelerating halide mixing upon annealing. During operational illumination, TDB undergoes transformation to form a new species with stronger adsorption on the perovskite grain-boundary surfaces, which inhibits the formation of iodide-related defects, suppresses defect-assisted carrier trapping and ion migration, thereby mitigating light-induced halide segregation4–6. The representative WBG perovskite (Eg = 1.88 eV) solar cell achieved a power conversion efficiency (PCE) of 20.01%, with an open-circuit voltage of 1.42 V, a fill factor of 85.13% and improved stability under illumination. By integrating the WBG perovskite solar cell into a monolithic perovskite–organic TSC, we achieved a PCE of 28.80% with a certified steady-state PCE of 28.04%. The perovskite–organic TSC retained 90% of its initial PCE after 625 h of operation under the ISOS-L-1 protocol. This is a preview of subscription content, access via your institution Access options Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any time Subscribe to this journal Receive 52 print issues and online access $199.00 per year only $3.83 per issue Rent or buy this article Prices vary by article type from$1.95 to$39.95 Prices may be subject to local taxes which are calculated during checkout Author information Authors and Affiliations Corresponding authors Supplementary information Supplementary Information (download PDF ) This file contains Supplementary Figures 1–47, Supplementary Tables 1–9, and Supplementary References. Rights and permissions About this article Cite this article Wu, R., Qin, S., Zou, T. et al. Perovskite–organic tandem solar cells with a photo-transformable stabilizer. Nature (2026). https://doi.org/10.1038/s41586-026-10869-x Received: Accepted: Published: DOI: https://doi.org/10.1038/s41586-026-10869-x