Scheme 1.

Schematic synthesis of chiral MOFs and CPL-active MOFs. Hmim and chiral histidine could coordinate with Zn ion to form chiral MOF. Various emitters, such as organic dyes, inorganic quantum dots (QDs), and lanthanide-doped upconversion nanoparticles (UCNPs), could be loaded into the chiral MOF by a simple in situ synthesis approach. The resulting emitter-loading chiral ZIFs could emit full-color circularly polarized light by tuning types of dyes or QDs, and white-color circularly polarized emission could be obtained. Additionally, upconverted circularly polarized luminescence (UC-CPL) based on achiral UCNPs and chiral MOF composites was achieved under 980 nm laser excitation.