Reactive force field simulations of silicon clusters

Abstract

The fast and continuous growth of multidisciplinary approaches, consisting of the combination of various experimental techniques and computational methods tuned on purpose to depict and predict material properties and performance, is motivated by the need to design new superior devices for effective applications in a great variety of industrial sectors. This strategy not only produces excellent results but is also fundamental to drive the research towards innovative and cost-effective production systems. In this short review we outline the major steps of our theoretical modelling activity connected to the experimental gas-phase synthesis of silicon nanoparticles (SiNPs) in plasmas reactors, limiting the discussion to the long-scale simulations based on the classical reactive description (ReaxFF methodology) for reproducing the whole process, perturbations included. The huge computational workload at the quantum chemistry level, required to prepare the training data, calibrate the parameters and validate the procedure, is not reported for the sake of conciseness. The excellent agreement of the simulations results with the experimental data and the sound explanations of the observed phenomena suggest that the ReaxFF-based paradigm is a reliable approach capable of studying these types of materials on time and size scales corresponding to realistic scenarios. Major steps of the theoretical modelling activity connected to the experimental gas-ase synthesis of silicon nanoparticles (SiNPs) in plasmas reactors.

Investigation of the stability and charge states of vacancy in clusters Si29 and Si38

“…Despite the fact that the vacancy in crystalline silicon has been studied for a long time using various methods, a relatively little attention is paid to the presence and stability of the vacancy in silicon nanoparticles. Although a number of researches on vacancy in nanosilicon have been provided [11][12][13][14], detailed studies of its geometric configuration and positions of electronic levels were done only in several of them [13,15]. Thus, size effects on the vacancy formation energy and entropy were considered in [13] and it was found that the size reduction makes the vacancy much easier to form; then, the vacancy concentration increases with reducing size and increasing temperature.…”