Electrodeposition of Aluminum Nanowire Arrays for Ultraviolet Surface Plasmonics

Well-developed nanoscale fabrication techniques for metals such as silver and gold have produced continuous, high-aspect ratio, short-pitch nanowire arrays and other nanostructures with high precision, capable of sustaining localized and propagating plasmonic resonances tunable from infrared to visible wavelengths. However, the interband transition properties of noble metals limit their implementation into the ultraviolet regime, promulgating alternative metals like aluminum, which has a Drude-like response in the UV. We implement a lithographically patterned nanowire electrodeposition technique to produce Al nanowire arrays with high aspect ratio and controlled, sub-200 nm cross sections. The cross sections are directly tunable by the electrodeposition bias and time, and resulting arrays demonstrate promising plasmonic resonances in the UV for future plasmonic waveguide, biological sensor, and photovoltaic applications.