Tuning the Optical Properties of CsPbBr₃ Nanocrystals by Anion Exchange Reactions with CsX Aqueous Solution.

ABSTRACT: Topotactic anion exchange has been developed to tune the composition and band gap energies of cesium lead halide (CsPbX₃) perovskite nanocrystals (NCs). However, current anion exchange methods either require harsh conditions or take a long time to realize substantial substitution. Here, we present a method to modulate the composition of colloidal CsPbBr₃ NCs through ultrasonication-assisted anion exchange with CsX (X?=?Cl, I) solution. Efficient anion exchange of CsPbBr₃ NCs with Cl^- or I^- is realized with substitution ratio up to 93% and preservation of the pristine shape and structure of CsPbBr₃ NCs. This anion exchange results in tunable emission, covering the whole visible spectral range, with relatively high photoluminescence quantum yield, narrow emission bandwidths, and good stability. This work provides a facile and efficient way to engineer the properties of halide perovskite NCs and has great potential for large-scale production of compositionally diverse perovskite NCs.

SUBMITTER: Yan A 

PROVIDER: S-EPMC6010365 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature