Boosting circularly polarized luminescence by optimizing off-centering octahedral distortion in zero-dimensional...

Chiral zero-dimensional hybrid metal halides (0D HMHs) are being extensively studied as they can directly generate circularly polarized luminescence (CPL) with high photoluminescence quantum yields (PLQYs), yet improving their luminescence dissymmetry factor (g _lum) remains a challenge. This study proposes a general strategy to boost the g _lum value of chiral 0D HMHs by optimizing the off-centering distortion of inorganic octahedra. Accordingly, (R/S-MBA)₂(2MA)In_0.95Sb_0.05Cl₆ (MBA = α-methylbenzylammonium, 2MA = dimethylamine) and (R/S-MBA)₂(3MA)In_0.95Sb_0.05Cl₆ (3MA = trimethylamine) with near-unity PLQYs are accordingly synthesized. With increasing the from 0.012 to 0.020, the |g _lum| is accordingly increased from 7.8 × 10^-3 to 2.0 × 10^-2. Notably, the |g _lum| can be further boosted to an impressive value of 3.8 × 10^-2 while maintaining near-unity PLQYs by continuously increasing the . Experimental results reveal that the choice of achiral ligands and varied Sb³⁺ dopant concentrations can modulate the distribution and strength of hydrogen bonds around indium-antimony halogen octahedra, respectively, thus regulating the parameter of octahedra in 0D hybrid metal halides. Additionally, light-emitting diodes with a polarization of 1.6% are fabricated. This work sheds light on the relationship between the distortion of inorganic octahedra and the g _lum value.