A Level Set Simulation for the Strain-Driven Sharpening of the Island Size Distribution during Heteroepitaxy

We use an island dynamics model for heteroepitaxial growth to study the narrowing and sharpening of the island size distribution as a function of the strain in the submonolayer growth regime. Our island dynamics model is coupled to an elastic model that is based on atomistic harmonic interactions. The elastic equations are solved self-consistently at every timestep during the simulation for the entire system. This is possible because the numerical timesteps in the island dynamics model that is based on the level set technique are significantly larger than the timestep of a typical atomistic event such as adatom diffusion and detachment, while we still retain all the relevant physics that are associated with adatom diffusion and detachment.