Plasmonic near-field coupling induced absorption enhancement and photoluminescence of silver nanorod arrays

Abstract

Silver nanorod (Ag NR) arrays with average diameter about 18 nm and period about 50 nm were electrodeposited in anodic aluminum oxide (AAO) templates. The filling factor of Ag NRs in the AAO nanopores could be adjusted by the deposition temperature. The filling factor increased to ∼98% when the deposition temperature decreased to 1 °C. As the filling factor increased, the plasmon absorption intensity of Ag NR arrays was greatly enhanced, and the longitudinal surface plasmon resonance increased faster. Meanwhile, the AgNR:AAO exhibit strong photoluminescence at ∼570 nm, obviously different with that of the bare AAO at ∼495 nm. Our observation revealed the strong near-field plasmon coupling among the Ag NR arrays.