Electrically driven plasmonic nanorod metamaterials (Conference Presentation)

Abstract

Electron tunnelling is a quantum-mechanical effect which allows the transport of electrons across a nanoscale junction between two conducting electrodes. During the tunnelling process, the broadband fluctuation in the tunnelling current can excite surface plasmons－the collective oscillations of free electron gas－in metallic nanostructures, providing an alternative way for the excitation of plasmons with advantages such as high compactness, fast response, and free of background. While the relatively low electron-to-plasmon conversion efficiency in single tunnel junctions can be improved by the design of nanostructure, high-density and large-scale tunnel junctions are highly required for the convenience of signal detection in practical applications. Here, by taking advantage of the high-density Au nanorod array, we demonstrated facile and large-scale electrical launching of surface plasmons in plasmonic nanorod metamaterials based on inelastic electron tunneling. Moreover, by harvesting the simultaneously generated hot electrons, we show that the light emission (radiative decay of plasmons) can be dynamically modulated due to the hot-electron-activated chemical reactions in the junctions.