Near-infrared circularly polarized luminescence (NIR-CPL) holds great promise for advanced photonic applications, however, simultaneously achieving both high photoluminescence quantum yield (PLQY) and large asymmetry factor ( g lum ) in the NIR region remains challenging owing to the energy-gap law. Herein, we propose a chiral quantum-cutting strategy based on rare-earth ion-doped chiral perovskite quantum dots (PeQDs). Specifically, the obtained chiral PeQDs exhibit strong NIR-CPL at 985 nm with both a large g lum of 0.092 and high PLQY of 157.2%, resulting in an exceptional figure of merit (FM = | g lum | × PLQY) of 0.145, representing the highest value among the reported chiral perovskites. The femtosecond-transient absorption spectra confirmed an ultrafast energy transfer accompanied by efficient spin preservation owing to the chirality-induced spin selectivity (CISS) effect, which resulted in the imbalanced spin population of Yb 3+ ions and enabled efficient NIR-CPL. Therefore, for the first time, we proposed and demonstrated the concept of chiral quantum-cutting effect and revealed the mechanism of spin flip and preservation during energy and chirality transfer based on the CISS effect. Our work provides a novel strategy for designing efficient NIR-CPL materials with large g lum and high PLQY, opening new avenues for developing high-performance chiral optoelectronic and spintronic devices in the NIR region.
Liu et al. (Tue,) studied this question.