A thermodynamic model based on a modified Classical Nucleation Theory is applied to the formation of colloidal metal and semiconductor nanocrystals. The predictions of the model are compared to experimental results published in the literature and well-established kinetic models, indicating an overall good accuracy. The definition of a potential energy curve that characterizes the system allows the prediction of the final (equilibrium) size of crystals as well as their size distribution. Furthermore, the nucleation process is studied in terms of key parameters affecting the concentration of crystals and is found to be related to the change in critical energy of stable nuclei during nucleation. Threshold values for the nuclei concentrations are predicted, defining instability and metastability conditions for the nucleation process. This model can help in refining our understanding of the mechanisms behind nucleation and growth of nanocrystals, with the goal of optimizing the fabrication process for industrial-scale production of nanocrystals and nanocrystal-based devices.
