Nature Energy, Published online: 10 September 2026; doi:10.1038/s41560-026-02135-1

Ultrawide-bandgap perovskites suffer from heterogeneities during crystallization. Zhang et al. use solvent and additive engineering to smooth the process for 2.0-eV bandgap perovskites, enabling 30.1% efficiency in all-perovskite triple-junction solar cells.