Plasmon resonance spectroscopy of gold-in-gallium oxide peapod and core/shell nanowires.

Light-scattering properties of individual gold-in-Ga(2)O(3) peapod nanowires and gold-in-Ga(2)O(3) core/shell nanowires were investigated by optical dark-field microscopy. The observed scattering peaks are suggested to result from plasmonic resonance of the gold nanopeas and nanorods in the Ga(2)O(3) nanowires. As the diameter of gold peapod increases, the resonance peak of the optical scattering spectra showed a red-shift. In addition, as the gold peas are elongated along one axis, the corresponding plasmon resonance peak splits into two peaks at shorter and longer wavelengths. The cladding Ga(2)O(3) dielectric layer also plays a key role in light-scattering behavior. The observed modulation in the p-polarized spectrum revealed that future vertical nanoplasmonic devices made by plasmonic nanocavity due to the short propagation length of surface plasmons can be realized and optimized.