Molecular dynamic study on silicon by using different force field models in supercooled region: A comparative analysis

Silicon is a tetrahedral substance where the central atom is connected with four faces by an angle of [Formula: see text]C. This substance shows many industrial applications, including chips and solar cells industries. The silicon usually exists in three different phases (i.e., solid, liquid and vapor) depending on the operating thermodynamic conditions. Apart from the major phases mentioned above, it shows the existence of low-density liquid (LDL), high-density liquid (HDL), low-density amorphous (LDA) and high-density amorphous (HDA) phases by distinguishing them based on their density. The substance may be referred to by the corresponding physical state (i.e., HDL, LDL, HDA and LDA) for particular targeted or desired applications. Based on the existence of the various physical states of silicon, it is important to understand and investigate its thermodynamic behavior, specifically under a supercooled region. Furthermore, the tetrahedral substance (i.e., silicon) represents the density and heat capacity anomalies in the supercooled state/region, which usually refers to the region close to liquid–liquid phase transition temperature ([Formula: see text]). Hence, by considering all the above aspects, in this study, we have focused on understanding and investigating the thermodynamic changes and their dependency on phase change phenomena under the supercooled region (i.e., close to [Formula: see text]). Furthermore, from the comparison perspective, we have performed this study by employing three different potential models (i.e., the Stillinger–Weber (SW) Potential Model, the Environment-Dependent Inter-atomic Potential (EDIP) Model and the Tersoff Potential Model). All the predicted results of this study are consistent in showing the independence of the thermodynamic changes while transforming from one phase to another (i.e., HDL to LDL) with respect to the corresponding force field model and liquid–liquid phase transition temperature ([Formula: see text]). All the corresponding results reported here are significant which shows the interesting observations on SW-silicon, EDIP-silicon and Tersoff-silicon under the supercooled region, which may further be applicable to define the best quality of silicon at [Formula: see text] for many desired industrial applications.