Growth patterns in electrodeposition

In that short review of growth processes in electrodeposition, we aim at discussing the relevant physical and chemical mechanisms which are likely to influence the dynamics of these growth processes and the morphology of the electrodeposits obtained in thin gap geometries. Electrodeposition has been early recognized as a paradigm experiment for reproducing diffusion-limited aggregation (DLA) morphologies as produced by the model of Witten and Sanders. The obvious similitude between DLA clusters and thin gap electrodeposits for some parameter values opened some fundamental issues about the correspondence of these experimental systems with DLA processes. We want to address in this paper the greater complexity of an electrodeposition process, in particular as far as the interfacial chemical and electrochemical kinetics is concerned. Our discussion is illustrated by an experimental analysis of copper electrodeposition in thin gap cells, based on interferometric, spectroscopic and optical inspection of both the deposit morphology and its composition and of the concentration fields around the deposit. Supported by these experimental investigations of copper electrodeposition in thin gap cells, we show that chemistry based argumentations are unescapable to explain the observed dynamical processes.