Moiré Engineering of Interlayer Coupling in WS2/MoS2 Monolayers

Moiré superlattices enable the modification of electronic band structures and material properties by tuning interlayer couplings, holding great potential for designing multifunctional optoelectronic devices in color tuning, light harvesting, and light generation. While theoretical predictions suggest that moiré potentials can control interlayer couplings in heterostructures, experimental realizations remain challenging due to difficulties in dynamically manipulating moiré potentials. Here we systematically modify interlayer couplings in a WS2/MoS2 heterobilayer by adjusting the excitation power and gate voltage to control moiré potentials. Increasing excitation power reduces the effective moiré potentials by influencing the filling of moiré traps, which suppress interlayer charge transfers and the p-doping effect on the WS2 from the heterostructure. Additionally, power-dependent PL measurements at varying gate voltages demonstrate a prominent decrease in the heterostructure's sublinear slope, from 0.63 (no voltage) to 0.52 (VG = 50 V), indicating enhanced moiré localization effects. This observation is verified by theoretical simulations of gate-tuned moiré potentials.