Highly Efficient Blue-Emission by Regulating the Hydrogen Bond Structure in Lead Halide Perovskites

Low-dimensional organic–inorganic hybrid perovskites (OIHPs) have attracted extensive attention due to their outstanding photoluminescence properties. However, the charge transfer between the organic A-site and the inorganic framework is impeded, resulting in lower photoluminescence quantum yield (PLQY). Herein, m-xylylenediamine (MXD) is incorporated into the perovskite, realizing the synthesis of a series of 0D perovskite-like single crystals, i.e., (MXD) 2 PbX 6 (X = Cl, Br, I). Density functional theory (DFT) calculations reveal the presence of effective hydrogen bonding between MXD and [PbX 6 ] 4− , which is enhanced through the controlled modification of halogen sites, enables the establishment of efficient charge transfer channels, and facilitates charge migration. Accordingly, (MXD) 2 PbCl 6 achieves a PLQY as high as 55.9% at 460 nm, characterized by blue light emission and remarkable air stability.