A kinetic Monte Carlo investigation of island nucleation and growth in thin-film epitaxy in the presence of substrate-mediated interactions

Island nucleation and growth during thin-film epitaxy is typically described using mean-field rate equations, which can be solved to predict the density of stable islands as a function of the deposition rate and the diffusivity of an isolated adatom. Recent theoretical and experimental studies indicate that medium- and long-range interactions between adatoms may change the simple picture that nucleation theory provides, because the presence of these interactions invalidates some of its assumptions. In this work, we investigate the ramifications of medium-range, substrate-mediated interactions for aspects of island nucleation and growth. The interactions are quantified for Ag on a strained Ag(111) substrate using density-functional-theory calculations. We discuss our incorporation of these interactions into a kinetic Monte Carlo model to study thin-film epitaxy. The simulated thin-film growth is compared to predictions by standard nucleation theory. We discuss features of island nucleation and growth that are actuated by the presence of medium-range interactions.