Ultra-stable, multimodal, and reversible luminescence switching in 0D Mn(II)-based hybrid halide nanofiber film for photonic applications.

The multifunctional and reversible stimuli-responsive luminescence switching offers significant potential for advanced photonic applications but presents considerable challenges for zero-dimensional (0D) hybrid halides. In this study, we design two 0D Mn(II)-based hybrid halides, (DMAP)MnCl·HO and (DMAP)MnCl (DMAP = protonated 4-dimethylaminopyridine), which demonstrate reversible photoluminescence (PL) and radioluminescence (RL) switching through the removal/insertion of guest HO and single-crystal to single-crystal (SC-SC) transformation. By employing a one-step electrospinning strategy, the composite nanofiber film benefits from geometric confinement and the superior hydrophobicity of the PVDF matrix, exhibiting excellent reversible PL switching properties, remarkable repeatability (1000 cycles), and rapid response to breath (0.6 s). Notably, the composite nanofiber film achieves a rare triple-mode reversible PL switching, including off-on (green), color-tunable on-on (green-yellow), and on (yellow)-off modes. This innovative composite holds great potential for novel applications in molecular-level dynamic photonic devices, including data storage, information security, optical logic gates, and flexible X-ray imaging.