Multicolor emission from a 0D-doped hybrid halide (C₈H₁₄N₂)₂CdBr₆ single crystal

Achieving multicolor emission is a fascinating goal that remains challenging for zero-dimensional (0D) hybrid halides. We successfully obtained a three-millimeter-scale 0D (MXDA)₂CdBr₆ (MXDA = C₈H₁₄N₂²⁺) single crystal (SC) by the solvothermal method. It serves as an outstanding host for doping with various valence activators, such as Cu⁺, Mn²⁺ and Sb³⁺, and these doped single crystals emit blue (470 nm), yellow (580 nm) and red (618 nm) fluorescence, which accurately cover a large visible region and achieve efficient multicolor emission. (MXDA)₂CdBr₆:8%Cu⁺ exhibits a high photoluminescence quantum yield (PLQY) of 60.31% under 320 nm UV excitation, while (MXDA)₂CdBr₆:10%Mn²⁺ shows a PLQY of 50.52%. Density functional theory calculations indicate that the hybrid 0D (MXDA)₂CdBr₆ halide is an indirect bandgap semiconductor with a bandgap value of 3.33 eV. This work expands the new material space for organic-inorganic hybrid halide materials and provides insights for tuning their optical properties.