Localized surface plasmon mode-enhanced spectrum-tunable radiation in electrically driven plasmonic antennas

摘要

A spectrum-tunable source with ultra-small volume is highly desired by on-chip information processing technologies. As a promising candidate, light emission from electrically driven tunnel junctions has gained much interest. In this Letter, using a gap bowtie antenna-based metal-insulator- metal junction as the source, multiple peaks are found in the electroluminescence spectrum of the antenna system. We attribute the peaks observed in the experimental emission spectrum to resonant plasmon modes that are supported by the antennas. This explanation is confirmed numerically by finite difference time domain calculations and analytically by using a theory imitated from scanning tunneling micros- copy. Our results show that the localized surface plasmon modes can be finely tuned by varying the gap distances and the geometries of the antennas, which eventually contribute to a spectrum-tunable light source. This Letter may provide a path for spectrum-tunable electrically driven light sources on photonic devices. (C) 2020 Optical Society of America