Electrochemical fabrication of anodic aluminum oxide films with encapsulated silver nanoparticles as plasmonic photoconductors

Two dimensional photoconductors based on anodic aluminum oxide (AAO) films with 80 nm pore size and 100 nm inter-pore spacing encapsulated with silver nanoparticles have been electrochemically fabricated. A 405 nm laser was used to illuminate the encapsulated silver nanoparticles through a transparent AAO barrier layer to induce photocurrent proportional to the laser power and applied voltage between two electrodes. The photoconductivity is attributed to plasmonic coupling among neighboring silver nanoparticles. The AAO barrier layer provides protection to encapsulated silver nanoparticles against possible degradation by the ambient environments and makes the device useful for biomedical sensors and electro-optical applications.