Designing Novel Electronic and Optoelectronic Properties in 2D Layered Materials by Strain and Plasmonic Engineering

In this talk we will show that valley-Hall transistors based on nanoscale strain-engineered monolayer graphene can exhibit quantum oscillations as well as quantum valley-Hall and quantum anomalous Hall effects (QVHE and QAHE) in the absence of any external magnetic fields. These findings associated with strain-induced giant pseudo-magnetic fields (PMFs) can pave the way towards realizing low-dissipative topological electronics, spintronics and optoelectronics in graphene with controlled strain superlattices. We will also demonstrate that the use of plasmonic vortices and backgate voltages can dramatically enhance the photoluminescence intensity and the degree of valley polarization in monolayer transition-metal dichalcogenide (TMD) WS₂ at room temperature. This approach can be further employed to develop novel opto-valleytronic/spintronic devices for topological photonic applications. Finally, we will describe new strategies to optimize the electronic and photonic properties of monolayer TMDs by post-CVD processing.