Pressure-induced robust emission in a zero-dimensional hybrid metal halide (C₉NH₂₀)₆Pb₃Br₁₂

Zero-dimensional (0D) hybrid metal halides are under intensive investigation owing to their unique physical properties, such as the broadband emission from highly localized excitons that is promising for white-emitting lighting. However, fundamental understanding of variations and structure–property relationships still limited. Here, by using pressure processing, we obtain robust exciton in 0D (C9NH20)6Pb3Br12 at room temperature can survive 80 GPa, recorded highest value among all halides. In situ experimental characterization first-principles calculations reveal pressure-induced mainly caused largely suppressed phonon-assisted nonradiative pathway. Lattice compression leads phonon hardening, which considerably weakens exciton–phonon interaction thus enhances emission. The attributed structure separated spring-like [Pb3Br12]6− trimers, outstanding stability optically active inorganic units. Our findings not only abnormally a halide, but also provide new insight into design optimization local structures trimers oligomers low-dimensional materials.