Zn(II) Alloying Improves the Luminescence Efficiency of Hybrid Tetrahedral Mn(II) Halides ((DMAPH)₂MnX₄; X = Cl, Br, and I) to Near-Unity

Zero-dimensional (0D) tetrahedral Mn(II) halides (MnX42– (X = Cl, Br, I)) have emerged as solid-state green emitters with high photoluminescence quantum yield (PLQY). However, their PLQYs are significantly dependent on the environment surrounding Mn(II), i.e., organic cation and halide. Although bromide is highly emissive, iodide exhibits relatively low PLQY. Herein, we report preparation of organic–inorganic hybrid (Cl, I) using protonated 4-dimethylaminopyridine ((DMAPH)+), they all exhibit bright luminescence PLQY (∼76%–80%), regardless halide ion. Surprisingly, DMAPH undergoes N-demethylation exclusively in case iodide. Furthermore, find that controlled Zn2+-doping/alloying lattice improves to near-unity (∼88%–94%) stable for more than 60 days. The increase excited state decay time time-resolved PL lifetime measurements revealed improved due reduced Mn(II)–Mn(II) interactions upon replacing some Zn(II). This further supported by Zn-alloying-induced hyperfine splitting ions observed electron paramagnetic resonance (EPR) measurements. excess alloying reduces decrease concentration lattice. These results demonstrate fabrication single crystals provide design strategies improve selective cations doping/alloying.