One‐step Synthesis of UV‐Curable CsPbX3 (X = Cl, Br, and I) Nanocrystal Inks for Printing

Abstract Metal halide perovskite nanocrystals (NCs) have garnered significant attention due to their captivating optoelectronic properties. One promising application for these materials is their use as color‐conversion layers (CCLs) in blue micro‐LED technology, enabling the realization of full‐color displays. Nonetheless, a pivotal challenge revolves around producing efficient luminescent perovskite inks and subsequently employing them for inkjet printing finely patterned CCLs. In this study, a straightforward single‐step hot‐injection method is introduced for synthesizing inks comprising CsPbX 3 NCs, where X represents Cl, Br, and I, or mixed halide systems such as Cl/Br and Br/I. Through precise composition control, the emission spectra can be effortlessly adjusted across the entire visible spectrum, spanning from 410 to 710 nm. The resulting CsPbX 3 NCs exhibit narrow emission line‐widths, ranging from 21 to 39 nm, an expansive color gamut encompassing up to 130% of the National Television Standards Committee color standard, and exceptional quantum yields reaching up to 100%. With their superb optical performance, facile synthesis procedure, and robust stability, these CsPbX 3 NCs emerge as highly suitable candidates for their use as CCLs with blue light‐emitting devices deployed as backlights.