Sequential and Reversible Phase Transformations in Zero-Dimensional Organic-Inorganic Hybrid Sb-based Halides towards Multiple Emissions

Zero-dimensional (OD) metal halides have drawn increasing attention due to the attractive structure dependent photoluminescence (PL) properties. Here, we report two new OD organic-inorganic hybrid Sb-based halides, (MTP)(6)SbBr6Sb2Br9 center dot H2O (MTP = Methyltriphenylphosphonium, crystal 1) and (MTP)(2)SbBr5(crystal 2), featuring a reversible structural phase transformation and tunable orange and red emissions upon dehydration and rehydration of H2O molecules. Intriguingly, a subsequent heat treatment further enables the formation of glassy state (MTP)(2)SbBr5 (glass 3) with near-infrared luminescence, moreover, a sequential reverse phase transformation from glass 3 to crystal 2 and 1 is triggered by acetonitrile and water vapor stepwise. The anti-counterfeiting demo based on the tunable and reversible PL switching is finally achieved and thus the phase structure engineering in OD metal halides expands their multiple applications in optical fields.

Automated summary

This study reports two new OD organic-inorganic hybrid Sb-based halides with reversible structural phase transformation and tunable emissions. The color of emissions can be changed by dehydration and rehydration, and a glassy material with near-infrared luminescence can be formed by heat treatment.