Isotope Engineering of Moire Superlattices in Twisted Bilayers of 2D Materials

Isotope engineering represents a smart strategy to modulate the properties of technologically significant materials without altering their chemical composition. In this project, we propose preparing isotopically clean 2D materials and assembling them in bilayer heterostructures. We will primarily focus on 12C/13C graphene and Mo/WS2 with the variation of 34S/32S isotopes. The isotopically engineered homo- and hetero-bilayers with random and controlled twist angles will be prepared on the substrate (SiO2/Si, hBN) and as suspended membranes. The typical characterization will include AFM, SEM, HRTEM microscopies, advanced Raman spectroscopy, and photoluminescence techniques (low temperature, magnetic field, chirality-resolved, timeresolved, tip-enhanced). Finally, we aim to explore the isotope effect on conventional and Moire excitons, valley polarization, and phonon-driven processes, such as thermal conductivity, in  the context of strain, doping, and defects.