Colloidal Synthesis and Optical Properties of Cs 2 CuCl 4 Nanocrystals.

Lead-free copper halide perovskite nanocrystals (NCs) are emerging materials with excellent photoelectric properties. Herein, we present a colloidal synthesis route for orthorhombic Cs₂CuCl₄ NCs with a well-defined cubic shape and an average diameter of 24 ± 2.1 nm. The Cs₂CuCl₄ NCs exhibited bright, deep blue photoluminescence, which was attributed to the Cu(II) defects. In addition, passivating the Cs₂CuCl₄ NCs by Ag⁺ could effectively improve the photoluminescence quantum yield (PLQY) and environmental stability. [ABSTRACT FROM AUTHOR]