Reversible Asymmetric Deformation Modulating Dexter Energy Transfer in Manganese Halide Perovskite with...

Deformation of metal halide perovskite can induce many interesting properties. This study focuses on a manganese-based organic-inorganic perovskite with a unique structure in which tetrahedral and octahedral coordination coexist in single crystal unit cell. This perovskite emits at 519 and 615 nm at room temperature. In contrast to conventional perovskites, this perovskite regulates the Dexter energy transfer between the two coordination modes through asymmetric deformation without phase transition, producing a reversible and tunable photoluminescence. Notably, under atmospheric pressure, as temperature increases from liquid nitrogen temperature to 135 °C, the luminescence color shifts progressively from red with a CIE coordinate of (0.59, 0.27) to yellow green with a CIE coordinate of (0.33, 0.56), with excellent reversibility. Additionally, at room temperature, the luminescence color shifts progressively from orange with a CIE coordinate of (0.54, 0.42) to red with a CIE coordinate of (0.61, 0.27) as pressure increases from 1 atm to 7.5 GPa. This novel tetrahedral and octahedral coexisting perovskite has a temperature-pressure equivalence effect in modulating luminescent color changes. It tunes emission by forming asymmetric deformations through the contraction (or expansion) of tetrahedra and expansion (or contraction) of octahedra upon stimulation, providing a new pathway to tune the emission of perovskites.