Narrow-Band Violet-Light-Emitting Diodes Based on Stable Cesium Lead Chloride Perovskite Nanocrystals

CsPbCl3 nanocrystals are potential ultrapure emitters. But it is challenging to synthesize with sufficient stability, which impedes their application in light-emitting devices. In this work, we report a facile phosphoryl-chemistry-mediated synthesis approach synthesizing stable nanocrystals, the phenylphosphonic dichloride (PhPOCl2) precursor employed. addition high reactivity of P–Cl bond PhPOCl2 for providing adequate Cl, derived P=O good proton affinity facilitates formation distinct nanocrystal surface nonprotonated oleylamine (OLA) ligand. Accordingly, L-type-ligand-capped exhibited not only bright luminance but also stability that endured repeated purification up 10 cycles. Based on achieved violet LEDs extremely narrow electroluminescence spectra (full width at half-maximum ≈ 10.6 nm).