In this work, we systematically investigated intralayer and interlayer excitonic photoluminescence in bilayer WS 2 using a dual-gate device architecture. By independently tuning the top and bottom gate voltages, without absolute calibration of carrier density or out-of-plane electric field, we examined the evolution of excitonic emission under temperature variation, equal-bias and opposite-bias gating configurations. Temperature-dependent measurements reveal that low-energy emission originates primarily from Γ-Q indirect excitons and their phonon replicas, whereas high-energy emission exhibits markedly greater thermal stability. Equal-bias gating induces substantial spectral weight redistribution between intralayer and interlayer excitons, accompanied by pronounced asymmetric responses to electron versus hole accumulation. Opposite-bias gating generates an effective perpendicular potential difference, resulting in a continuous redshift of interlayer exciton energy, while intralayer excitons display distinctly different tuning behavior. These contrasting responses highlight fundamental differences in electric dipole moments and many-body interactions between the two excitonic species. Our findings uncover the rich excitonic landscape of bilayer WS 2 and provide a robust experimental platform for electrical control of excitonic states in two-dimensional semiconductors.
Wang et al. (Wed,) studied this question.