Intrinsic self-trapped broadband emission from zinc halide-based metal-organic frameworks

Organolead halide perovskites are an emerging class of intrinsic self-trapped broadband emitters, but suffer from lead toxicity and stability problems. Herein, we report a series of metal-organic frameworks (MOFs) based on 0-D zinc halide secondary building units (SBUs), which emit large Stokes shifted broadband bluish-white light. A variety of photophysics studies demonstrate that the broadband emission probably originates from self-trapped excitons, owing to the structurally deformable SBUs. Among the intrinsic self-trapped emitters, these MOFs are very rare examples that exhibit both long-term environmental stability and contain non-toxic elements. Moreover, the open porosity enables the MOF to serve as a host matrix for encapsulating green-emitting Alq3 molecules, exhibiting cold white-light chromatic coordinates of (0.27,0.36) and a correlated color temperature of 8321 K.