Long-Range Exciton Transport in Perovskite-Metal Organic Framework Solid Composites

The encapsulation of perovskite quantum dots (PQDs) in metal organic frameworks (MOFs) is a promising strategy for fabricating stable and functional perovskite solid composites (denoted as PQDs@MOF), which have exhibited great potential for optoelectronics, catalysis, and luminesce applications. However, the exciton diffusion distance, one of the key factors determining the performance of PQDs@MOF in these applications, remains unknown. Herein, by using time-resolved and photoluminescence-scanned imaging microscopy, we report the observation of long-distance exciton transport (278 ± 12.6 nm) and high diffusion coefficient (0.0428 ± 0.0039 cm²/s) in MAPbBr₃ PQDs@MOF microcrystals. We show that the long exciton diffusion length, which is seven times longer than that in colloid MAPbBr₃ PQD solid films, can be attributed to the strong dipole-dipole coupling between adjacent PQDs embedded in the MOF matrix and their long carrier lifetimes. These findings demonstrate the great potential of PQDs@MOF crystals for optoelectronic applications.