Fluorine Polymer‐Modified Dion‐Jacobson Perovskites Enabling Sky‐Blue Perovskite Light‐Emitting Diodes with an Efficiency of 16.55%

Abstract Quasi‐2D Dion‐Jacobson (DJ) perovskites are promising candidates for fabricating high‐performance blue‐emitting perovskite light‐emitting diodes (PeLEDs) because of their strong quantum/dielectric confinement and high stability. However, obtaining high‐efficiency blue PeLEDs based on DJ perovskites remains a major challenge. Herein, sky‐blue DJ perovskites are synthesized by using 1,8‐diamino‐3,6‐dioxaoctane as an organic diamine and high‐quality perovskite films are prepared by incorporating poly(vinylidene fluoride‐ co ‐hexafluoropropylene) (PVDF‐HFP) as an additive, aiming to improve the photoluminescence quantum yield and electron carrier mobility of the film used as an emissive layer in PeLEDs. Finally, sky‐blue PeLEDs using PVDF‐HFP‐modified DJ perovskite films are demonstrated to show a high maximum external quantum efficiency of 16.55%. A promising strategy is provided to design high‐quality perovskite films for constructing high‐performance blue PeLEDs.