Self-assembly from the branch pattern to parallel wire array in electrodeposition

Abstract

We report a self-organized copper electrodeposition without imposed templates and induced additives. The deposit morphology on the silicon substrate varies from a branch to a parallel pattern by changing the applied voltage. We suggest that there are two essential factors for the formation of such kind of copper wire arrays. One is a proper electric potential distribution near the tip of the copper wire which dictates the direction of the solute transport. The other one is that the cathode overpotential and the equilibrium potential of reaction should remain unchanged at the growing interface.

Oriented hydroxyapatite single crystals produced by the electrodeposition method

“…9). The broadening of the PO 4 3− adsorption bands observed after 15 min of deposition suggests that in this case the coating was constituted by a not organized HA. The adsorption bands become sharper as the crystals grow.…”

“…Zhang et al [4] have analyzed the growth of cooper nano-wires by electrodeposition on silicon substrates. They have shown that an equipotential distribution of lines near Cu-wire tips reaches a critical value and therefore optimum deposition conditions can be defined at certain voltage.…”

“…For instance, one might expect the surface roughness to generate charged regions, which are very susceptible to transfer electrons. Therefore, the structure of the coating would be significantly affected [4]. In order to minimize this effect, we have decided to employ polished surfaces (Fig.…”

“…A distance of 6 cm between Pt-counter electrode and the substrate was fixed. Electrolysis has been carried out in an aqueous solution (pH initial ∼4.5) containing 0.61 mol L −1 of Ca 2+ [Ca(NO 3 ) 2 )] and 0.36 mol L −1 of PO 4 3− [NH 4 H 2 PO 4 ], under stirring. A constant current density of 0.318 mA/cm 2 has been imposed for 3 h at 90 • C. After deposition, all specimens were rinsed with distilled water and ethanol and then dried at 100 • C for 12 h.…”

“…The oriented coating growth with ordered two-and three-dimensional structures have been intensively investigated due to their applications in several domains, including electronic systems [4] and biological purposes [3,5,6]. It has been shown that cells have an increased sensitivity to nano/microscale patterns [7,8], and are influenced by the material crystallinity [9].…”