Morphologies of copper deposits obtained by the electrodeposition at high overpotentials

Morphologies of copper deposits obtained at overpotentials belonging to the plateau of the limiting diffusion current density and at higher overpotentials were examined by the scanning electron microscopy (SEM) technique. Copper dendrites are formed at overpotentials belonging to the plateau of the limiting diffusion current density. The shape of copper dendrites depends on the electrodeposition overpotential. At higher overpotentials (800 and 1000 mV) and larger values of current densities, porous and very disperse copper deposits were obtained. These morphologies were a consequence of a very vigorous hydrogen evolution at these electrodeposition overpotentials. Also, the obtained copper structures consisted of agglomerates of copper grains. The size of copper grains is a function of the overpotential of electrodeposition, thus approaching to nano-sized dimensions is achieved when the electrodeposition overpotential is increased.