To realize small footprint and high speed nanoelectronics, the plasmonics based tunneling electrons have been shown as a potential technology. In general, surface plasmons have been demonstrated that they are able to be directly excited by tunneling electrons in different ways including scanning tunneling microscopes (STMs), metal–insulator–metal junctions using vacuum or metal oxides or molecular tunneling barriers. The direct excitation of plasmons by tunneling electrons is attractive because, on the one hand, there is no background light generated, and on the other hand this approach is feasible to develop fast devices (on the timescale of quantum tunneling) as no slow electron–hole recombination processes are required.
In this talk we will report our recent development of theoretical frameworks to model and simulate the direct excitation of plasmons based on tunneling electrons with respect to different metallic and graphene plasmonic structures. First the directional excitation of electrical-plasmon propagating surface plasmons on a periodic 1D Au cavity by a STM will be addressed [1]. Second thanks to electron tunneling in self-assembled monolayers (SAM), the on-chip molecular electronic plasmon sources consisting of tunnel junction 2nm-layer of SAM sandwiched between two metallic electrodes that excite plasmons will be discussed in detail [2]. Third, by using 2nm-metal oxide layer in MIM junction, we will demonstrate that on-chip electronic-plasmonic transducers can be achieved to efficiently generate, manipulate and transfer plasmons [3]. Last, we will demonstrate that the graphene is potentially a highly efficient material for tunneling excitation of plasmons because of its narrow plasmon linewidths, strong emission, and large tunability in the mid-IR wavelength regime [4].