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

Abstract 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.