Hybrid Metal Halides with Multiple Photoluminescence Centers

Very little is known about the realm of solid-state metal halide compounds comprising two or more halometalate anions. Such compounds would be of great interest if their optical and electronic properties could be rationally designed. Herein, we report a new example of metal halide cluster-assembled compound (C₉ NH₂₀ )₉ [Pb₃ Br₁₁ ](MnBr₄ )₂ , featuring distinctly different anionic polyhedra, namely, a rare lead halide cluster [Pb₃ Br₁₁ ]⁵⁻ and [MnBr₄ ]²⁻ . In accordance with its multinary zero-dimensional (0D) structure, this compound is found to contain two distinct emission centers, 565 nm and 528 nm, resulting from the formation of self-trapped excitons and ⁴ T₁ -⁶ A₁ transition of Mn²⁺ ions, respectively. Based on the high durability of (C₉ NH₂₀ )₉ [Pb₃ Br₁₁ ](MnBr₄ )₂ upon light and heat, as well as high photoluminescence quantum yield (PLQY) of 49.8 % under 450 nm blue light excitation, white light-emitting diodes (WLEDs) are fabricated, showcasing its potential in backlight application.