Multiple Responsive CPL Switches in an Enantiomeric Pair of Perovskite Confined in Lanthanide MOFs

Circularly polarized luminescence (CPL) switches have attracted widespread attention due to their potential applications in advanced information technologies. However, the design and fabrication of solid‐state multiple‐responsive CPL switches remain challenging. Here, through self‐assembly of chiral metal‐organic frameworks (MOFs) and perovskite nanocrystals (NCs), a pair of crystalline enantiomeric (P)‐(+)/(M)‐(−)‐EuMOF⊃MAPbX3 (MA = CH3NH3+, X = Cl−, Br−, I−) adducts is prepared, where the achiral MAPbBr3 perovskite NCs embedded into chiral MOFs inherit the chirality of host MOFs by host‐guest EuBr and PbO coordination bonds, which is demonstrated by synchrotron‐radiation‐based X‐ray absorption spectroscopy. The chiral adducts show enhanced photoluminescence quantum yield (PLQY), good thermal stability of CPL in air, and photoswitchable CPL properties upon altering different UV irradiation. Based on two chiral emission centers and their different characteristics, reversible CPL switches are realized upon a diversity of external stimuli, for example, chemicals (water /CH3NH3Br solution) or temperatures (room temperature/high temperature). Benefiting from the extraordinary stimuli‐responsive and highly reversible switchable CPL, multiple information encryptions and decryptions integrated with CPL, together with a chiroptical logic gate are successfully designed. This work opens a new avenue to generally fabricate solid‐state CPL composite materials and develops new applications based on switchable CPL. Achiral perovskite nanocrystals (NCs) are embedded in homochiral metal‐organic frameworks (MOFs) for color‐tunable circularly polarized luminescence (CPL) without any ligand passivation. Experimental results indicate that MAPbBr3 NCs adopted a chiral packing in enantiomeric MOFs by EuBr and PbO bonds. The CPL of composites possesses the multiple external‐stimulate responsive reversibility.