2p interlayer exciton revealed by hybridization in bilayer MoS2

Interlayer excitons—bound electron–hole pairs residing in separate layers—feature long lifetimes and Stark-tunable energies, making them promising for excitonic devices and dipolar quantum phenomena. While most prior studies have focused on the 1 s ground state, here we reveal the 2 p interlayer exciton along with a Rydberg series of interlayer states extending from 1 s to 4 s in bilayer MoS ₂ . The 2 p state, optically dark at zero field, acquires oscillator strength under an applied electric field through hybridization with the intralayer A exciton. Due to its finite angular momentum, it exhibits distinct selection rules and g -factors in agreement with theoretical expectations. Strikingly, whereas the intralayer Rydberg series fades beyond the 2 s state, the interlayer series remains optically visible up to 4 s . This extended visibility arises from hybridization with the intralayer B exciton, which transfers oscillator strength to higher interlayer states and effectively brightens the entire series. Simulations further uncover a novel coupling mechanism between s -like intralayer and p -like interlayer excitons—one driven not by conventional electron–hole Coulomb interactions, but by interlayer conduction band mixing. These findings establish bilayer MoS ₂ as a versatile platform for exploring tunable excitonic phenomena.