Synthesis and luminescence mechanism of 1D organic metal halides with mixed single-stranded and double-stranded chains

Abstract

Low-dimensional organic metal halides (LD-OMHs) have garnered significant attention due to their remarkable application prospects in solid-state lighting, displays, and optoelectronic sensing, attributed to their advantages of cost-effective synthesis, tunable bandgaps, and efficient emission properties. In this study, we have synthesized a one-dimensional (1D) mixed-structure single crystal 1 (Pb₂Br₉(C₅H₇N₅)₄PbBr₅·2H₂O) by self-assembly using organic cations with different functional groups. The synthesis of the mixed-structure single crystal 1 involves not only the effects of the different functional groups but also the synergistic interactions between these groups and H₂O molecules, which together lead to the self-assembly of the 1D-OMH mixed-structure single crystal. 1 exhibits a high photoluminescence quantum yield (PLQY) of 42.20% and a high color rendering index (CRI) value of 81. The composition of the single- and double-stranded chain mixed structures increases the level of octahedral distortion and alters the band structure, thereby facilitating the recombination of carriers and significantly enhancing the PLQY. Our work provides a new pathway for improving the PLQY of 1D-OMHs and a new insight into the structure–property relationships of 1D-OMHs.