One‐Step Preparation of Ion‐Doped Cesium Lead Halide Perovskite Nanocrystals by Ultrasonication

Abstract CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) are competitive materials for a wide range of applications because of their outstanding optoelectronic properties. Ion doping has been demonstrated as one powerful method for improving the optical properties of CsPbX 3 NCs. However, the conventional ion‐doping approaches are tedious, and generally performed under an inert atmosphere and high temperature. In this work, a one‐step ultrasonic‐assisted approach is demonstrated to prepare doped CsPbX 3 NCs. To demonstrate the universality of the ultrasonic‐assisted ion‐doping approach, three ion‐doped perovskite NCs are prepared, which represent three common improvements effects of ion doping on perovskite NCs, namely improved stability, PL emission, and photoluminescence quantum yields (PLQYs) of perovskite NCs. Sr‐doped CsPbI 3 NCs showed improved phase stability. Mn‐doped CsPbCl 3 NCs showed dual‐color emissions at 406 and 580 nm. The PLQYs of the as‐prepared Ni‐doped CsPbCl 3 NCs are greatly improved, from 10.1% to 71%. Such a simple and versatile ion‐doping approach may promote the practical applications of all‐inorganic perovskite NCs.