Two Novel Two-Dimensional Organic-Inorganic Hybrid Lead Halides with Broadband Emission for White-Light-Emitting Diodes

Low-dimensional organic-inorganicmetal halides(LOMHs)recently have attracted much attention due to their tunable crystalstructures and excellent photoelectric properties. The configuration and arrangement of organiccations in LOMHs have significant effect on the structure of inorganicframeworks and luminescence properties. In this work, we systematicallyexplored the spatial effect and hydrogen bondingeffect of organiccations on the structure and properties of LOMHs, by synthesizingthreeLOMHs including (N-AD)PbCl4, (N-AD)(2)Pb2Br7, and (N-AD)(4)Pb3I12 (N-AD: N-acetylethylenediamine, C4H10N2O). Specifically, (110)-oriented two-dimensional (N-AD)PbCl4 and (N-AD)(2)Pb2Br7 with manifestblue-white emissions, originating from the free excitons (FEs) andself-trapped excitons (STEs), respectively. The UV-pumped light-emittingdiode (LED)-based on (N-AD)(2)Pb2Br7 was prepared, and the highest color rendering index (CRI) and correlatedcolor temperature (CCT) were up to 80 and 4484 K, respectively. Thisproves its potential application in solid-state lighting.

Automated summary

Low-dimensional organic-inorganic metal halides (LOMHs) have gained significant attention for their tunable crystal structures and excellent photoelectric properties. This study systematically investigates the spatial and hydrogen bonding effects of organic cations on the structure and properties of LOMHs. Three LOMHs were synthesized and their blue-white emissions were attributed to free excitons (FEs) and self-trapped excitons (STEs). An ultraviolet-pumped light-emitting diode (LED) based on one LOMH showed high color rendering index (CRI) and correlated color temperature (CCT), demonstrating its potential in solid-state lighting.