Monte Carlo simulation of linear aggregate formation from CdTe nanoparticles

Abstract

In recent works it was found that nanometre sized particles of CdTe could spontaneously reorganize into crystalline nanowires (NWs) upon controlled removal of the protecting shell of organic stabilizer in an aqueous medium. At present, there is no possibility of predicting for certain the outcome of each particular NW self-assembly experiment or influencing the geometric parameters of the aggregates. A model for the simulation of the interaction of CdTe nanoparticles (NPs) and their aggregation into clusters has been developed and a Monte Carlo simulation was performed. A ‘linearity coefficient’ has been developed and introduced into the model that allows for the comparison of NP aggregate geometries and investigation of the dependence of aggregate shapes on NP charge and dipole strength. The simulation results show that the presence of a dipole moment is crucial to the formation of chain-like NP aggregates. The shapes of the clusters that were obtained during simulations resemble those seen in the experiment, although serious differences are still observed, which hint at the influence of other, most probably, short-range interparticle forces on the clustering process.