Room‐temperature phosphorescence (RTP) has attracted considerable attention due to its potential applications in light‐emitting, bioimaging, and chemical sensing devices, but it is full of challenges to achieve new molecular systems for efficient RTP. Herein, three imidazole derivatives involving triplet excitons as organic cations are employed to synthesize three isostructural 1D lead halides with distinct emission characteristics, in which (2‐MBI)PbBr3 and (2‐PI)PbBr3 show the blue and broadband white fluorescence, respectively, while (5‐MBI)PbBr3 (5‐MBI = 5‐methylbenzimidazole) exhibits efficient green RTP peaking at 520 nm under UV excitation. The underlying photophysical regulatory mechanism is unveiled that extra‐molecular “heavy atomic effects” and the spin–orbit coupling from [PbBr3−]∞ units enhance the intersystem crossing and Dexter‐type electron transfer of excitons from inorganic units to triplet states (Tn) in 5‐MBI cations. An information encryption pattern is also realized by combining the different photoluminescence of these 1D organic and inorganic hybrid lead halides. This study suggests a feasible strategy to modulate the photoluminescence to achieve efficient RTP in low‐dimensional hybrid metal halides.

Low-dimensional organic–inorganic metal halides (LOMHs) recently have attracted much attention due to their tunable crystal structures and excellent photoelectric properties. The configuration and arrangement of organic cations in LOMHs have significant effect on the structure of inorganic frameworks and luminescence properties. In this work, we systematically explored the "spatial effect" and "hydrogen bonding effect" of organic cations on the structure and properties of LOMHs, by synthesizing three LOMHs including (N-AD)­PbCl4, (N-AD)2Pb2Br7, and (N-AD)4Pb3I12 (N-AD: N-acetylethylenediamine, C4H10N2O). Specifically, (110)-oriented two-dimensional (N-AD)­PbCl4 and (N-AD)2Pb2Br7 with manifest blue-white emissions, originating from the free excitons (FEs) and self-trapped excitons (STEs), respectively. The UV-pumped light-emitting diode (LED)-based on (N-AD)2Pb2Br7 was prepared, and the highest color rendering index (CRI) and correlated color temperature (CCT) were up to 80 and 4484 K, respectively. This proves its potential application in solid-state lighting.

Lead-free low-dimensional organic-inorganic hybrid metal halides (OIMHs) have been widely concerned in solid-state lighting (SSL) on account of their excellent photoluminescent properties and stability. Herein, we synthesized a new zero-dimensional...

No abstract