Wang, YuruiLin, RenxingWang, XiaoyuLiu, ChenshuaiyuAhmed, YameenHuang, ZilongZhang, ZhibinLi, HongjiangZhang, MeiGao, YuanLuo, HaowenWu, PuGao, HanZheng, XuntianLi, ManyaLiu, ZhouKong, WenchiLi, LudongLiu, KaihuiSaidaminov, Makhsud I.Zhang, LijunTan, Hairen2025-01-232025-01-232023Wang, Y., Lin, R., Wang, X., Liu, C., Ahmed, Y., Huang, Z., Zhang, Z., Li, H., Zhang, M., Gao, Y., Luo, H., Wu, P., Gao, H., Zheng, X., Li, M., Liu, Z., Kong, W., Li, L., Liu, K., . . . Tan, H. (2023). Oxidation-resistant all-perovskite tandem solar cells in substrate configuration. Nature Communications, 14(1). https://doi.org/10.1038/s41467-023-37492-yhttps://doi.org/10.1038/s41467-023-37492-yhttps://hdl.handle.net/1828/20984The commonly-used superstrate configuration (depositing front subcell first and then depositing back subcell) in all-perovskite tandem solar cells is disadvantageous for long-term stability due to oxidizable narrow-bandgap perovskite assembled last and easily exposable to air. Here we reverse the processing order and demonstrate all-perovskite tandems in a substrate configuration (depositing back subcell first and then depositing front subcell) to bury oxidizable narrow-bandgap perovskite deep in the device stack. By using guanidinium tetrafluoroborate additive in wide-bandgap perovskite subcell, we achieve an efficiency of 25.3% for the substrate-configured all-perovskite tandem cells. The unencapsulated devices exhibit no performance degradation after storage in dry air for 1000 hours. The substrate configuration also widens the choice of flexible substrates: we achieve 24.1% and 20.3% efficient flexible all-perovskite tandem solar cells on copper-coated polyethylene naphthalene and copper metal foil, respectively. Substrate configuration offers a promising route to unleash the commercial potential of all-perovskite tandem solar cells.enAttribution 4.0 InternationalArticleDepartment of Chemistry