Carrier Dynamics in Nano-Metallic, Hot-Electron-Based Photon Energy Conversion Enhanced by Heterogeneously-Coupled Surface Plasmon Polaritons (II)(1/2)

While metallic, hot-electron-based photon energy conversion has been drawing much attention in the past few years, enhanced photon energy conversion via heterogeneously-coupled surface plasmon plaritons (SPPs) and/or the co-existence of SPPs and gap plamons, as well as carrier transport in nano-metallic films/structures remains relatively unexplored. On the basis of what we have developed in theoretical formalism and experimental demonstrations in the past few years, the proposed research will explore the time-resolved carrier dynamics in nano-metallic films/structures in the framework of hot-electron-based photon energy conversion enhanced by gap plasmons and heterogeneously-coupled SPPs. Key areas of investigations are the dependence of conversion efficiency enhancement on structural symmetry and resonant excitations/coupling, carrier transport formalism for carrier relaxation time estimates in nano-metallic structures, nanofabrications of a novel plasmonic photodetector, targeting a measured external quantum efficiency of up to >2% as a preparation for pump-probe measurements in the future. Carrier transport theory based on an electron wavepacket and extremely short interaction time will be developed. In addition, opto-electro-thermal interactions in the photon energy conversion process will also be investigated in order to reveal the limiting factors of the conversion efficiency. All the effort leads to extending the knowledge of non-ballistic transport in nano-metallic, hot-electron-based photon energy conversion and of optimum device designs in favor of minimum inelastic collision losses. The results will also provide sufficient data for assessing potential applications of such devices in both conventional and non-telecom-window, short-reach, ultra-high-speed optical interconnects.