Electrochemical Growth of Copper Nanowires Inside of Semiconducting TiO2 Nanotubes

Abstract

Growth of metal/oxide nanowires inside of semiconducting nanotubes has several applications for energy storage and energy conversion. In this study, the bottom-up growth of copper nanowires through electrodeposition techniques was studied as a method to fill TiO2 nanotube arrays. Specifically, emphasis was placed on the study of copper containing electrolyte solution kinetics through inhibitor and accelerator additives commonly used in the damascene process. It was observed that the electrical conductivity and wetting characteristics of the TiO2 nanotubes played significant roles in the bottom-up growth of copper nanowire deposition. The electrolytes commonly used in the damascene process were found not to be useful for direct copper deposition inside of the TiO2 nanotubes. Higher pH solution of CuSO4 with tartaric acid as a complexing agent and pulsed deposition conditions showed promising results for copper deposition within the TiO2 nanotubes.