Researchers reached a certified efficiency of 29.3% in all-perovskite triple-junction solar cells by combining surface reconstruction with halide homogenization, according to reporting published in Nature Energy. The process addresses physical degradation in ultrawide-bandgap perovskites, which remain essential components for building high-efficiency triple-junction solar harvesting devices.
Ultrawide-bandgap formulations require high bromide content to operate, but that chemistry regularly causes surface wrinkling and halide disorder across the film. These dual structural flaws directly suppress device performance. The authors resolved the defect by reconstructing the perovskite surface and homogenizing the distribution of halides, enabling the triple-junction cells to achieve the certified 29.3% efficiency figure.
Tomoya Nakamura, Minh Anh Truong, and Atsushi Wakamiya conducted the research across Kyoto University's Institute for Chemical Research and the HIKARI-COOL Kyoto project at the Kyoto University Institute for Advanced Study. Wakamiya serves as co-founder and chief advisor for science and technology at EneCoat Technologies Co. Ltd., located in Kyoto. The remaining co-authors declared no competing financial interests in the publication.
Nature Energy published the peer-reviewed study on 10 September 2026 under DOI 10.1038/s41560-026-02127-1, citing related energy harvesting studies published between 2022 and 2026 by Hu, Lin, and Zhang. Springer Nature sells single articles for $1.95 to $39.95, alongside a 30-day online tier for $32.99. A full annual subscription costs $119.00 for 12 digital issues, or $9.92 per issue.
