Defect Engineering in Large Area Epitaxial Monolayer MoS₂ for Optoelectronics and Beyond

Monolayers of transition metal dichalcogenides (TMDCs), due to their tunable properties, have shown immense promise in applications such as optoelectronics, flexible electronics, spintronics and energy harvesting. Defect engineering has emerged as a facile tool to tune the properties of monolayer TMDCs making them more potent for these applications. While a high propensity of defects is useful for certain applications like catalysis, many other applications benefit from low defect densities. Thus, understanding the nature of these defects as well as finding quick throughput techniques to characterize them have become critical. Additionally, although several efforts have focused on creation/healing of defects, these processes are still premature and not well understood. In this talk, we will discuss defect engineering in large area epitaxial monolayer MoS 2 thin films. We will outline in-situ approaches for fabrication/healing of defects. We will also demonstrate a quick throughput technique to characterize defect densities in these thin films. We envision the ability to modulate defect densities (create/heal) in a controllable fashion in these materials can open-up an additional knob to tune the opto-electronic properties of these materials thus making them more marketable for applications in opto-electronics, photonics, energy harvesting and beyond.