Kinetic analysis for formation of Cd_1-xZn_xSe solid-solution nanocrystals

Kinetic analysis on the nanocrystal solid-solution formation was performed by heat treating CdSe/ZnSe core/shell nanocrystals, synthesized via a typical TOP/TOPO approach, at different temperatures for different time periods. X-ray diffraction (XRD) peak shifts in Cd_1-xZn_xSe cores according to the solid-solution treatments were monitored and used for the estimation of the lattice parameter change. The degree of solid-solution formation was determined considering the compositional variation in Cd_1-xZn_xSe cores, which was obtained from the Vegard's law. The degree of solid-solution formation (x) was applied to Jander analysis, and an Arrhenius-type plot was produced using the slopes of Jander plots. The activation energy for solid-solution formation was determined as 152 kJ/mol, which evidently indicates that the diffusion of Zn²⁺ ions in the CdSe-ZnSe system is the governing mechanism for the Cd_1-xZn_xSe solid-solution formation. The Jander equation to predict the solid-solution formation kinetics for the CdSe/ZnSe core/shell systems was completed using the reaction rate constant (k).