Strongly Fluorescent Quaternary Cu–In–Zn–S Nanocrystals Prepared from Cu_1-<i>x</i>InS₂ Nanocrystals by Partial Cation Exchange

Abstract

We report a high-yield, low cost synthesis route to colloidal Cu1-xInS2 nanocrystals with a tunable amount of Cu vacancies in the crystal lattice. These are then converted into quaternary Cu–In–Zn–S (CIZS) nanocrystals by partial exchange of Cu+ and In3+ cations with Zn2+ cations. The photoluminescence quantum yield of these CIZS nanocrystals could be tuned up to a record 80%, depending on the amount of copper vacancies.