Enabling Efficient Blue‐Emissive Circularly Polarized Luminescence by In Situ Crafting of Chiral Quasi‐2D Perovskite Nanosheets within Polymer Nanofibers

Abstract Chiral perovskite materials have intrigued enormous interests because of their appealing chiroptical properties and tailorable non‐centrosymmetric structures. However, it remains challenging to realize high‐efficiency blue emissive circularly polarized luminescence (CPL) of intrinsic chiral perovskite nanomaterials at room temperature. Herein, a robust and versatile electrospinning strategy is reported for in situ construction of chiral 2D and quasi‐2D perovskite nanosheets (PNSs) protected in polymer hybrid nanofibers. It is found that quasi‐2D chiral PNS/polymer possesses inherent chirality and enhanced CPL properties at room temperature compared to 2D counterparts. Notably, CPL emission color of chiral quasi‐2D PNS/polymer can be tuned from deep blue to sky blue, and a high luminescence dissymmetry values up to −8.0 × 10⁻³ can be achieved. Different perovskites, polymers, and nanofibrous structures are expanded to explore the universality of polymer protected PNSs. Significantly, compared to spin‐coated film, the stabilities of quasi‐2D PNS/polymer film are greatly improved due to the effective protection of polymer. The obtained PNS/polymer hybrid nanofiber films can be conveniently implemented for circularly polarized light emitting diode devices. This study may open up a new avenue for the scalable fabrication of chiral perovskite nanomaterials of interest and their applications in the CPL related fields.