センチメートルサイズの耐水性青色発光ゼロ次元ハイブリッドハライド固体照明用

Zero-dimensional (0D) organic-inorganic hybrid halides exhibit attractive excitonic emission properties, but their environmental stability remains a major challenge. Here we report centimeter-sized single crystals of (MAPPA)CdBr₄·H₂O (MAPPA = protonated 1-methyl-4-(6-aminopyridin-3-yl)piperazine), which exhibit blue emission with a photoluminescence quantum yield of 46.7%. The emission is excitation-wavelength-independent, maintains an unchanged spectral profile under varying excitation powers and is governed by a temperature-driven balance between thermally activated blue emission and self-trapped exciton-mediated yellow emission. Time-resolved spectroscopy reveals moderate thermal quenching, while density functional theory calculations indicate that the emission originates from Br-4p → Cd-5s/Br-4p transitions. (MAPPA)CdBr₄·H₂O retains both luminescence and crystallographic integrity after extended exposure to water (50 days) and air (150 days), demonstrating notable environmental resilience. When integrated into a white light-emitting diode (WLED) with commercial phosphors, the material yields warm-white emission with a high color rendering index (91) and stable chromaticity across operating currents. These findings highlight (MAPPA)CdBr₄·H₂O as a robust 0D halide hybrid, offering valuable design insights for developing environmentally stable blue emitters for next-generation solid-state lighting.