Synthesis of Cd-free water-soluble ZnSe1−xTex nanocrystals with high luminescence in the blue region

Forming a thick shell through a heat treatment during irradiation, the photoluminescence efficiency of Cd-free core-shell nanocrystals (ZnSe1−xTex/ZnS) was increased to 40% and the emission peak was tuned into the pure blue range (448 nm). Quantum mechanical calculations revealed that the thick ZnS shell confines the electron inside the particle and then improves the PL efficiency and stability of nanocrystals.