Perovskite nanocrystals are attracting great interest due to their excellent photonic properties. Here, through a supramolecular self-assembly approach, the perovskite nanocrystals (NCs) with a novel circularly polarized luminescence (CPL) are successfully endowed. It is found that the achiral perovskite NCs can coassemble with chiral gelator in nonpolar solvents, in which the gelator molecules modify the surface of the perovskite NCs. Through such cogelation, the molecular chirality can transfer to the NCs resulting in CPL signals with a dissymmetric factor (g ) up to 10 . Furthermore, depending on the molecular chirality of the gelator, the CPL sense can be selected and the mirror-imaged CPL is obtained. Such gels can be further embedded into the polymer film to facilitate flexible CPL devices. It is envisaged that this approach will afford a new insight into the designing of the functional chiroptical materials.
In this work, lanthanide-doped upconversion
nanoparticles (UCNPs)
showing upconverted circularly polarized luminescence were demonstrated
in an organic–inorganic co-assembled system. Achiral UCNPs
(NaYF4:Yb/Er or NaYF4:Yb/Tm) can be encapsulated
into chiral helical nanotubes through the procedure of co-gelation.
These co-gel systems display intense upconverted circularly polarized
luminescence (UC-CPL) ranging from ultraviolet (UV, 300 nm) to near-infrared
(NIR, 850 nm) wavelength. In addition, the UV part of UC-CPL can be
used to initiate the enantioselective polymerization of diacetylene.
Metal–organic frameworks (MOFs) have attracted tremendous attention for several novel applications. However, functional MOFs with light‐responsive circularly polarized luminescence (CPL) are not examined in detail. Therefore, a dual CPL switch exhibiting both upconversion (UC) and downshifting (DS) CPL in the solid state is constructed by loading a luminescent diarylethene derivative (DAEC) and UC nanoparticles (UCNPs) into chiral MOFs. The chiral MOF⊃DAEC composites exhibit both photoswitchable luminescence and DS‐CPL properties under alternating UV and visible light irradiation. Additionally, a reversible UC‐CPL switch is realized using near‐infrared (NIR) and visible light irradiation by introducing energy‐level‐matched UCNPs and DAEC into the chiral MOFs. The dissymmetry factor (glum) of UC‐CPL is noted to be significantly amplified through energy transfer compared to that of DS‐CPL, which indicates that the information on circular polarization can be manipulated by altering the incident light. A chiroptical logic circuit with a 2D information output is designed with UV, visible, and NIR light as inputs by setting a rational threshold.
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