Morphological Surface Study of Silver Electrodeposition by Kinetic Monte Carlo-Embedded Atom Method

Herein, a kinetic Monte Carlo (KMC) simulation of the 3D electrodeposition of Ag metal on Ag cathode surface is carried out under galvanostatic, different substrate temperatures, and current density conditions. Both deposition and diffusion processes are considered during the film electrodeposition, where each adatom diffuses via nearest-neighbor hopping, exchange, and step-edge atom exchange mechanisms. The interatomic interaction is described within the well-known embedded atomic method (EAM) framework. The number of hopping, exchange, and step-edge exchange mechanisms is evaluated using a power law of time n hop proportional to t alpha , n exch proportional to t beta , and n step proportional to t gamma , respectively. However, the step-edge exchange mechanism depends on current density. The effects of deposited atom number, current density, and substrate temperature on the transitions of surface morphologies of the electrodeposited thin film are studied considering different combinations of the mechanisms. The results indicate that surface roughness increases when the number of deposited atoms and the current density increase, but when the substrate temperature increases the roughness decreases. In addition, the resulting surface has been found to be smooth if all diffusion mechanisms are involved in the electrodeposition phenomenon, while roughness occurs when diffusion takes place only via hopping mechanism. Furthermore, the surface roughness behavior is found to be related to clusters and islands distribution.

Automated summary

In this study, a kinetic Monte Carlo simulation was used to investigate the 3D electrodeposition of Ag metal on Ag cathode surface under galvanostatic conditions with different substrate temperatures and current densities. The deposition and diffusion processes were considered, and the interatomic interactions were described using the embedded atomic method (EAM) framework. The results showed that the surface roughness increased with the number of deposited atoms and current density, but decreased with substrate temperature. The behavior of surface roughness was found to be related to the distribution of clusters and islands.