Figure 1
From: Repeated Solid-state Dewetting of Thin Gold Films for Nanogap-rich Plasmonic Nanoislands
Au nanoislands and plasmon resonance shift depending on the diameter.
A schematic illustration for Au nanoislands from (a) a single-step solid-state dewetting and (b) highly dense and nanogap-rich Au nanoislands after repeated dewetting. Unlike a single-step solid-state dewetting of thin Au film, the repeated dewetting simply provides Au nanoislands with enlarged size but small gap spacing, which increase the packing density for strongly coupled and multiple electromagnetic hotspots. (c) the extinction and plasmon resonance shift depending on the diameter of Au nanoislands; the dashed curve shows the plasmon resonance wavelength shift as a function of the diameter and representative extinction spectra for D = 40 nm and D = 60 nm, respectively. Inset shows the electric field intensity distribution at the plasmon resonance wavelength for D = 40 nm and D = 60 nm, repectively. A substantial increase of the diameter in constant volume apparently contributes to an increase of the extinction intensity as well as a red-shift of the plasmon resonance wavelength.
