In Situ Synthesis of Core-Shell Structured Perovskite Nanofibers for Stretchable Color-Conversion Film

Recently, stretchable color-conversion films encapsulating organic-inorganic halide perovskite nanocrystals (PeNCs) have been developed. However, reported methods for fabricating stretchable perovskite films require multistep process, including the synthesis of PeNCs and their encapsulation within a protective matrix, followed by their incorporation into a stretchable matrix. To address these challenges, we introduce a one-step fabrication process based on coaxial electrospinning to produce stretchable perovskite fiber films. In this approach, PeNCs are in situ synthesized within a protective poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) core, which is subsequently encapsulated by a stretchable styrene-butadiene-ethylene-styrene (SEBS) shell. To investigate the effect of the SEBS shell, we also fabricated MAPbBr₃@PVDF-HFP fiber films without the SEBS shell. We observed that the SEBS shell enhances photoluminescence quantum yield (PLQY), stability and stretchability. The resulting MAPbBr₃@PVDF-HFP@SEBS fiber film exhibits superior optical properties (full width at half-maximum of ∼23 nm, PLQY of 61.4%), stability (retaining 94% of its emission intensity after 9 days in water), and stretchability (140% strain at break). We expect that this one-step fabrication method for stretchable color-conversion films can be applied to wearable displays in the future.