Boundary-induced nucleation control: a theoretical perspective

The pre-patterning of a substrate to create more attractive or repulsive regions allows one to generate a variety of structures in vapour deposition experiments, specific of technological relevant semiconducting organic molecules. A particular interesting structure is generated if the attractive region is forming a rectangular grid. For specific combinations of the particle flux, the substrate temperature and the lattice size it is possible to generate exactly one cluster per cell, giving rise to nucleation control. Here we show that the experimental observations of nucleation control can be very well understood from a theoretical perspective. For this purpose we perform, on the one hand, kinetic Monte Carlo simulations and, on the other hand, use analytical scaling arguments to rationalise the observed behaviour. Overall we present and verify the connection from an analytical description together with a simulation approach and show a direct comparison with experimental data. For several observables, characterising nucleation control, we find a very good agreement between experiment and theory. This underlines the universality of the presented mechanism to control the deposition of material by manipulation of the environment. Generalisations are discussed.