Growth of silver on zinc oxide via lattice and off-lattice adaptive kinetic Monte Carlo

Abstract

The growth of Ag on ZnO was modeled using a reactive force field potential and a combination of molecular dynamics and adaptive kinetic Monte Carlo (AKMC) simulations. An adaptive lattice-based AKMC model is described as a method of extending timescales and length scales that can be simulated. Reusing previously found transitions to reduce computational time is discussed for both the lattice and off-lattice AKMC approaches. With these methods, growth of over 1 monolayer’s worth of Ag is simulated corresponding to a real deposition time of up to 0.1 s. The results show that the deposited silver aggregates on the surface through mainly single atom moves with few concerted motions. Initially silver adatoms do not agglomerate and the energy barriers for silver dimers to form are larger than for them to break apart. The first layer of silver grows as a series of connected regions rather than forming well-defined centro-symmetric islands.