Molecular dynamics to model carbon infiltration into a porous silicon matrix: An experimental and computational approach

Abstract

In this work, a porous silicon matrix (PSm) and its functionalization with carbon atoms are modeled by molecular dynamics (MD); the simulation is correlated experimentally to analyze the model results. Computationally, the Tersoff potential for the silicon carbon system is used to build a model by MD using Large-scale Atomic/Molecular Massively Parallel Simulator free-source code (LAMMPS). First, a model of a PSm with an aleatory distributed macroporous was built; then, C atoms were injected into the PSm model to functionalize the matrix; finally, the model shows the functionalization of the PSm, forming carbon-silicon composites, which are Si clusters surrounded by C atoms. Experimentally, PSm was fabricated using samples of a p-type crystalline silicon wafer by electrochemical etching. A colloidal suspension of graphene oxide (GOs) was used as a source of carbon atoms: the GOs was added to the electrolyte, during the etching process, to functionalize the PSm with C atoms. AFM images show that the PSm pores are not obstructed after functionalization. Carbon-silicon composites were formed into the PSm samples according to X-ray diffraction and EDS characterizations. The results of the modeling agree with the results of the experiments.