Near-infrared and visible dual-band circularly polarized luminescence from chiral hybrid indium halides co-doped with Yb3+ and Sb3+
Chiral organic-inorganic hybrid metal halides (OIHMHs) are multifunctional materials with structural diversity and chiroptical properties. However, current chiral OIHMHs predominantly exhibit circularly polarized luminescence (CPL) in the visible spectrum, while ultraviolet and near-infrared (NIR) CPL remains challenging. Here, we report lead-free chiral zero-dimensional (0D) OIHMHs, (R/S-DACH)2In2Br10:Sb3+/Yb3+ (DACH = 1,2-diaminocyclohexane), featuring spectrally tunable CPL emissions covering visible to NIR regions. Single-crystal X-ray diffraction, circular dichroism, and CPL spectroscopy revealed that robust hydrogen-bonding interactions between organic cations and inorganic emitters are crucial for chirality expression. Sb3+-doped (R/S-DACH)2In2Br10 single crystals exhibited intense broadband emission at 644 nm from the 3P1 to 1S0 transition of Sb3+, achieving a record photoluminescence quantum yield (PLQY) of 49.9% (two orders of magnitude higher than pristine crystals) and a luminescence dissymmetry factor (glum) of ±7.1×10−3. Notably, Sb3+/Yb3+ co-doped crystals simultaneously generated dual-band CPL at 644 nm (glum = ±2.1×10−2) and 994 nm (glum = ±6.8×10−3), representing an important example of NIR-CPL in OIHMHs. An LED device based on (R-DACH)2In2Br10:2.7%Sb3+ exhibited bright orange emission with a color-rendering index of 78.4 and excellent spectral and operational stabilities. These findings establish a design strategy for broadband CPL and expand applications of chiral metal halides in advanced optoelectronics.