Stabilizing red-emitting all-inorganic perovskite nanocrystals by a ligand-mediated room-temperature procedure

Abstract

Although lead halide perovskite (LHP) nanocrystals (NCs) are considered propitious materials due to their extraordinary optoelectronic properties, the scalability of synthesis and poor ambient stability hinder their commercial applications. Herein, we develop a facile and universal room-temperature (RT) protocol for the synthesis of red-emitting all-inorganic CsPbBr_3−xI_x perovskite NCs by the mediation of capping ligands. The emission wavelength can be tuned in the range of 598–651 nm by tailoring the PbBr₂ : PbI₂ precursor ratios and the amounts of ligands. Interestingly, the introduction of ligands such as 3-mercaptopropionic acid (MPA) and thioglycolic acid (TGA) heavily improves the stability of the as-synthesized NCs against water, heat stress and UV irradiation, which is due to surface passivation. This work offers a reliable and scalable reference for tuning red-emissive perovskite NCs with improved environmental stability, which will accelerate their commercial application process in optoelectronic fields.