Vertical growth of plasmonic nanostructures via electrodeposition on a conductive oxide

Abstract

Metallic nanostructures have a variety of interesting properties and applications, especially as substrates for LSPR-based refractometric sensors for biological and chemical species. A common method for metal deposition is electron beam evaporation. However, this is limited to structures with heights on the order of tens of nanometers. Growth of tall structures for such sensors provides greater surface area for binding and increased interaction volume. Methods for creating taller structures are limited, with the most common method being electrodeposition. This is typically done on a nonconductive substrate by using a seed a layer of the metal to be grown, optionally with a thin adhesion layer using a metal such as chromium. In this work, we propose elimination of the need for a seed layer and its subsequent removal by directly electrodepositing onto a transparent conductive substrate suitable for plasmonic applications.