Polar Phase Enhanced Multistimuli-Stable PVDF-MAPbBr3@PbBr(OH) Microwire Composites

Organic-inorganic hybrid perovskite microwires can offer novel optical and anisotropic structural properties, but their operational stability remains limited when exposed to multiple environmental and operational stressors, including moisture, heat, irradiation, and mechanical deformation. In this work, a hierarchical PVDF-MAPbBr3@PbBr(OH) microwire composite was constructed through a core-shell-polymer synergistic encapsulation strategy. The solvent-resistant MAPbBr3@PbBr(OH) microwires can be embedded in poly(vinylidene fluoride) (PVDF) by room temperature spin coating. Experimental results confirm that the one-dimensional morphology and core-shell crystalline framework are retained during polymer encapsulation. Moreover, the MAPbBr3@PbBr(OH) microwire filler significantly regulates the PVDF chain conformation, increasing the β-PVDF content from approximately 60% to 86%. The enhanced polar phase, together with hydrophobic barrier protection and Pb-F interfacial coupling, contributes to improved interfacial stability and environmental durability. As a result, the PVDF-MAPbBr3@PbBr(OH) microwire composites exhibit highly stable photoluminescence under hot-water treatment, mechanical deformation and continuous LED operation. This work provides an effective interfacial phase-regulation strategy for developing hydrothermally stable and mechanically flexible perovskite luminescent microwires.