Speaker
Description
Two-dimensional semiconductor heterostructures provide a rich platform for exploring strongly bound excitons and interlayer coupling phenomena. In particular, moiré superlattices formed by stacking transition metal dichalcogenide (TMD) monolayers enable tunable hybridization between excitonic states across layers. We investigate the electrical-driven band evolution in WS$_2$/ MoSe$_2$ heterobilayers using photoluminescence (PL) and differential reflectance (DR) spectroscopy on dual-gate devices. Because the conduction band edges of WS$_2$/ MoSe$_2$ are nearly degenerate, the applied electricity strongly mixes their electronic states. As a result, the DR spectra exhibit pronounced Stark redshifts and clear splitting of the MoSe$_2$ exciton resonances, evidencing the formation of hybridized inter- and intralayer excitons. These excitons further experience moiré potential modulation, giving rise to additional fine structures and localization behavior within the superlattice. Our findings highlight the moiré superlattice as a versatile platform for engineering hybridized excitonic states with tunable coupling, offering new opportunities for exploring correlated exciton physics and electrical-controllable quantum optoelectronic phenomena.