Modeling and analysis of electrodeposition in porous templates

Controlling the morphology of materials grown via electrodeposition into porous templates remains a challenge, since the filling of the template often proceeds in a non-uniform manner, which is undesirable for applications such as nanowire fabrication. Here, we first develop a continuum phase-field approach for modeling electrodeposition into a porous template. We simulate growth within a single straight pore in order to study the fraction of the pore width filled by the deposit under various conditions, and then simulate growth within and overflowing a template composed of several straight pores. We reproduce experimentally observed cap morphologies and corresponding current transients, and find that when the template material is permeable to ionic diffusion, growth becomes more non-uniform. We also perform simulations of electrodeposition in pores with cross-sectional areas that vary over the height of the template, and show that the deposit homogeneity is strongly affected by variations in pore geometry. Finally, we carry out a statistical analysis of length distributions of electrodeposited nanowires extracted from experimental images. Such an analysis enables us to quantify, e.g., the pore-to-pore variations in nucleation times or growth rates required to yield the observed spread in nanowire lengths.