Computational modeling of electrolytic deposition of a single-layer silicon film on silver and graphite substrates

摘要

Electrodeposition of silicon from a KF-KCl-KI salt melt at 1000 K using silver and graphite substrates has been studied by the molecular dynamics method. Silicon films of monatomic thickness with a predominantly hexagonal honeycomb structure were obtained on each substrate. The adhesion energy between the obtained film and the silver substrate is 2.5 times higher than that between the film and the graphite substrate. A single cluster grows much faster on a graphite substrate than on a silver substrate, where several clusters are formed at once. As the substrates are filled with silicon, the diffusion coefficient of Si atoms decreases faster on a graphite substrate than on a silver one. The silver substrate is completely covered with silicon, while a three-dimensional Si cluster begins to grow on a graphite substrate incompletely filled with silicon. The obtained silicon films on both substrates do not have the characteristic buckling, which is found in silicene prepared by the chemical vapor deposition on a silver substrate. Films obtained on both substrates have low mechanical stress. The stress distribution in the case of a graphite substrate is more uniform.