Photoluminescence of Plasmonic Structures with Transition Metal Dichalcogenide Monolayers

Atomically thin transition metal dichalcogenide (TMD) layers and heterostructures demonstrate a potential for applications in two-dimensional transistors, sensors, and optoelectronic devices due to strong interactions with light, bandgap in the visible range, and controlled light-valley interactions. While TMD monolayers are proficient in light absorption due to a semiconducting phase where monolayers have a direct bandgap, they are still deemed as inefficient when it comes to practical applications. To mitigate this, we seek to enhance their performance by studying the effect of a nearby plasmonic structure on light absorption and emission by the TMD. Specifically, we explore photoluminescence and absorption (via differential reflectivity) spectra of MoSe₂ and WS₂ monolayers on a Si/SiO₂ substrate. Plasmonic structures with features ranging in size between 4–20 microns were deposited on the substrate before placing the TMD monolayers. We present these results as well as discuss the applications of the system to transduction of radiofrequency pulses to optical signals with this structure.