Luminescent Thin Films Enabled by CsPbX 3 (X=Cl, Br, I) Precursor Solution.

Inorganic cesium lead halide perovskite nanocrystals are candidates for lighting and display materials due to their outstanding optoelectronic properties. However, the dissolution issue of perovskite nanocrystals in polar solvents remains a challenge for practical applications. Herein, we present a newly designed one-step spin-coating strategy to prepare a novel multicolor-tunable CsPbX 3 (X=Cl, Br, I) nanocrystal film, where the CsPbX 3 precursor solution was formed by dissolving PbO, Cs 2 CO 3 , and CH 3 NH 3 X into the ionic liquid n-butylammonium butyrate. The as-designed CsPbX 3 nanocrystal films show high color purity with a narrow emission width. Also, the blue CsPb(Cl/Br) 3 film demonstrates an absolute photoluminescence quantum yields (PLQY) of 15.6 %, which is higher than 11.7 % of green CsPbBr 3 and 8.3 % of red CsPb(Br/I) 3 film. This study develops an effective approach to preparing CsPbX 3 nanocrystal thin films, opening a new avenue to design perovskite nanocrystals-based devices for lighting and display applications.