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

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)PbCl 4 , (N-AD) 2 Pb 2 Br 7, and (N-AD) 4 Pb 3 I 12 (N-AD: N-acetylethylenediamine, C 4 H 10 N 2 O). Specifically, (110)-oriented two-dimensional (N-AD)PbCl 4 and (N-AD) 2 Pb 2 Br 7 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) 2 Pb 2 Br 7 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.