Asymmetric plasmon structures on ZnO: Ga for high sensitivity in the infrared range

This paper presentssurface plasmons (SPs) onZnO: Ga layers using an asymmetric insulator-metal-insulator (IMI) geometry. The water-ZnO: Ga-cytop tri-layers comprising IMIstructures showed narrowersurface plasmon resonancespectra than insulator-metalstructures with water-ZnO: Ga single layers. Measurements of bulk sensitivities based onrefractive index changes revealed extended evanescent fields on theZnO: Ga layersurfaces when using reduced layer thicknesses. Consequently, the asymmetric IMI geometry onZnO: Ga provides enhanced sensitivity in the infrared range. This result is further discussed from theoretical analyses of SP field distributions. This IMI geometry providesstructural concepts to assist with developments in the area of oxide-based sensing applications.

Source: Applied Physics Letters - November 7, 2016 Category: Physics Authors: Hiroaki Matsui, Akifumi Ikehata and Hitoshi Tabata Source Type: research