Excited State Regulated Emission in Hybrid Indium Halides via Crystal Structure Switch

Organic-inorganic metal halides have become one of the most promising materials in the next generation of optoelectronic applications due to their high charge carrier mobility and tunable band gaps. In this study, Sb:PA(6)InCl(9) and Sb:PA(4)NaInCl(8) single crystals were prepared through evaporation crystallization, respectively. Due to the different degrees of lattice distortions, the highly efficient yellow emission in Sb:PA(6)InCl(9) at 610 nm and the green emission in Sb:PA(4)NaInCl(8) at 545 nm were achieved by regulation of the excited state, respectively. By introducing additional sodium ions in the post-treatment, we found that the zero-dimensional Sb:PA(6)InCl(9) could rapidly convert into a two-dimensional layered structure of Sb:PA(4)NaInCl(8), thus resulting in a novel green/yellow emission switch. This work guides the structural and performance control of organic-inorganic hybrid In-based metal halides and offers broad prospects for luminescent switching in anticounterfeiting applications.