Synthesis and characterization of colloidal ternary ZnCdSe semiconductor nanorods

摘要

For the synthesis of colloidal ternary ZnCdSe nanorods,CdSe nanorods were first prepared under a mixture of tetradecylphosphonic acid/trioctylphosphine oxide surfactants at 250 deg C,and then ZnSe shell layer was grown onto CdSe nanorods at 180 deg C,forming CdSe/ZnSe core/shell nanorods.Green-yellow emitting ternary ZnCdSe nanorods were obtained by a subsequent alloying process at 270 deg C for 1-3 h through the diffusion of Zn ions into CdSe nanorods.The photoluminescence quantum yield (QY) of ZnCdSe nanorods was 5%-10%,which is higher than that from pristine CdSe nanorods (0.6%).The QY of these alloy nanorods depends on the alloying time and is discussed in terms of compositional disorders and defects produced by the alloying process.The Raman and time resolved photoluminescence spectroscopies were used to understand the detailed alloying process from CdSe/ZnSe core/shell to ZnCdSe alloy nanorods.