Dispersion in water of CsPbBr3 perovskite nanocrystals by surface modification

The instability and clumping of lead halide perovskite nanocrystals in polar solutions have limited their practical use. In this paper, a convenient and effective surface modification strategy was applied to substitute the typical oleic acid (OA) with 3-bromopropionic acid (BPA) ligand for the one-step synthesis of CsPbBr3 NCs in the absence of any inert gas atmosphere with water as the non-solvent. Thanks to the synergistic effect of BPA and OAm on the surface of CsPbBr3 NCs, it has excellent dispersibility while exhibiting excellent stability in water. Even after being fully submerged in water for 168 h, the material can still emit a vibrant green light, and the emission peak position is stable at 520 nm. In contrast, the CsPbBr3 NCs of the OA ligand were completely burst in water within minutes. This study opens the door for the direct synthesis and preservation of CsPbBr3 NCs in the aqueous phase, which will be an important step in advancing their large-scale applications in extreme environments.