Photonic Metal-Organic Frameworks

Materials of metal-organic frameworks (MOFs) in pure and hybridized forms showing photonic properties have received much attention during past years. Strategies to prepare photonic MOF-based materials are constantly used as follows: 1) designing of pure MOFs with intrinsic luminescent units such as organic linkers and/or lanthanide ions; 2) designing of hybrid MOF composites through encapsulation of extrinsic luminescent units such as organic dyes and/or inorganic nanospecies; and 3) designing of MOF-based composites through mixing both intrinsic and extrinsic luminescent units to display synergistic effect. A highly ordered structure with the richness of space groups enable well-designed MOFs to display second-harmonic generation. In addition, easy formation of well-faceted morphology, to serve as optical microresonators in MOF crystals, is beneficial for the exploration of the miniaturization of lasers. Moreover, with the assistance of stepwise coating, devices fabricated by using MOF-based materials in lighting have been realized. Furthermore, biocompatible nanoscale MOF composites coated by polymers and encapsulated with photo-absorbing agents in cancer treatment are also discussed. This review provides a summary and discussion of the very recent progress of photonic MOFs in applications of white solid-state lighting, lasing, nonlinear optics, and phototherapy in cancer treatment.