Single‐Component White Emissive Organic–Inorganic Hybrid Copper Halide Composite Films for Remote UV‐pumped White Light‐Emitting Diodes with High Color Rendering Index

Abstract Lead‐free organic–inorganic metal halides (OIMHs) are highly desirable owing to their remarkable properties including low toxicity, structural diversity, high stability, and solution processability. Nevertheless, the development of their single‐component white emissive films remains a formidable challenge for remote white light‐emitting diodes (WLEDs) application. In this work, (C 16 H 36 N) 2 Cu 2 I 4 /polyvinylidene fluoride (PVDF) white emissive composite film is successfully fabricated through an in situ solvent evaporation crystallization process at room temperature. The elemental analysis and bonding between (C 16 H 36 N) 2 Cu 2 I 4 and PVDF are demonstrated by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) measurements. In addition, this composite film exhibits a broadband white emission with two peaks. Notably, the best photoluminescence quantum yields (PLQYs) of the PVDF based composite film reaches an impressive 96.7%. A (C 16 H 36 N) 2 Cu 2 I 4 /PVDF based remote UV‐pumped WLEDs with an impressive color rendering index of 95.5 is realized. Finally, the in situ fabrication method is expanded to fabricate (C 16 H 36 N) 2 Cu 2 I 4 /polyacrylonitrile (PAN) composite films, and we further realized their single component remote WLEDs.