Optical properties and plasmonic response of silver-gallium nanostructures
Résumé
Silver and gallium form an alloy Ag2Ga via a room temperature spontaneous self-assembly that
exhibits remarkable mechanical and electrical properties suitable for nanoscale measurements.
However, whether photon excitation of plasmons in this emerging nanomaterial is retained or not
has not been established. Here, we present a thin film formation of Ag2Ga via a spreading-reactive
process of liquid Ga on an Ag film and a characterization of its dielectric function !(E)¼!1(E)
þi!2(E) in the photon energy range 1.42 eV#E<4.2 eV. It is observed that while the plasmon
damping increases, near an energy of 2.25 eV, the real part of ! exhibits a crossing with respect to
that of Ag. Furthermore, the impact of new plasmon supporting materials is discussed and in order
to enable further applications in plasmonics, the possibility of photon excitation of surface plasmons
in Ag2Ga is studied.