Electrospun CsPbBr 3 Nanowire Fibers Enabling Highly Stable Flexible Polarized Luminescent Film

The liquid crystal displays (LCDs) based on backlighting technology dominate the flexible display market. However, the overall optical efficiency of conventional LCD systems is generally less than 5%, caused by the polarization conversion process. Therefore, replacing unpolarized backlight with intrinsically polarized emission sources represents a pivotal technological route to eliminate polarizer‐induced energy loss and improve the overall optical efficiency of LCDs. Herein, we adopted a facile electrospun strategy to encapsulate pre‐synthesized CsPbBr 3 nanowires (NWs) into polystyrene (PS) fibers, thereby fabricating the highly stable flexible polarized luminescent CsPbBr 3 NWs@PS fiber film. The resultant CsPbBr 3 NWs@PS fiber film exhibits prominent linearly polarized luminescence behavior, with the degree of polarization (DOP) reaching as high as 0.48. Specifically, the hydrophobic PS sheath acts as a physical barrier that efficiently suppresses ionic migration and concentration quenching effects within the encapsulated CsPbBr 3 NWs, leading to a 7.16‐fold enhancement in photoluminescence (PL) lifetime. In addition, the CsPbBr 3 NWs@PS fibers retain 95% of initial PL intensity after 300 days in an air environment. This work provides valuable experimental evidence and theoretical insights for the rational design and fabrication of high‐performance perovskite‐based highly stable flexible polarized luminescent films, which holds great promise for advancing the development of high‐efficiency LCDs and other polarized optoelectronic devices.