Dr. Ambrose Seo, University of Kentucky

Title: Shaping Light and Charge in Two-Dimensional Materials with Plasmonic Nanostructures

Abstract: Two-dimensional materials such as MoS2 are just one atom thick, which gives them remarkable optical and electronic properties, but also makes them challenging to use efficiently in devices, since their ultrathin nature limits how strongly they interact with light. During my sabbatical in Seoul, I explored new ways to overcome this challenge by combining MoS2 with carefully designed metallic nanostructures that can trap and guide light at the nanoscale. By embedding gold or silver nanowires and nanogrooves beneath or alongside MoS2, we found that we could significantly boost its light emission, collect photo-generated charges more effectively, and improve the efficiency of heterostructures that pair MoS2 with oxide semiconductors. These studies show how "plasmonic" effects, i.e., collective oscillations of electrons in metals, can be harnessed to control light–matter interactions in atomically thin materials. I will present the key outcomes of these projects and discuss how they point toward future opportunities for next-generation devices.