Blue Emitting Single Crystalline Assembly of Metal Halide Clusters

The rich chemistry of organic-inorganic metal halide hybrids has enabled the development of a variety of crystalline structures with controlled morphological and molecular dimensionalities. Here we report for the first time a single crystalline assembly of metal halide clusters, (C₉NH₂₀)₇(PbCl₄)Pb₃Cl₁₁, in which lead chloride tetrahedrons (PbCl₄^2-) and face-sharing lead chloride trimer clusters (Pb₃Cl₁₁^5-) cocrystallize with organic cations (C₉NH₂₀⁺) to form a periodical zero-dimensional (0D) structure at the molecular level. Blue light emission peaked at 470 nm with a photoluminescence quantum efficiency (PLQE) of around 83% was realized for this single crystalline hybrid material, which is attributed to the individual lead chloride clusters. Our discovery of single crystalline assembly of metal halide clusters paves a new path to functional cluster assemblies with highly tunable structures and remarkable properties.