Spectral Tuning of a Nanoparticle-on-Mirror System by Graphene Doping and Gap Control with Nitric Acid

• DOI: 10.1021/acsami.3c05302
• Publication Date: 2023-08-03T09:36:47Z
• Authors: Julia Lawless; Oisín McCormack; Joshua Pepper; Niall McEvoy; A. Louise Bradley

Nanoparticle-on-mirror systems are a stable, robust, and reproducible method of squeezing light into sub-nanometer volumes. Graphene is particularly interesting material to use as spacer in such it the thinnest possible 2D can be doped both chemically electrically modulate plasmonic modes. We investigate simple nanoparticle-on-mirror system, consisting Au nanosphere on top an mirror, separated by monolayer graphene. With this we demonstrate, with experiments numerical simulations, how doping graphene control gap size controlled tune response coupled using nitric acid. The coupling thin film reveals multipolar modes which tuned adjusting or intermediate monolayer. At high levels, interaction between charge-transfer plasmon leads splitting energies. study provides evidence for unification theories proposed previous works investigating similar systems.