2p interlayer exciton revealed by hybridization in bilayer MoS2

We reveal the 2p interlayer exciton along with a Rydberg series of interlayer states extending from 1s to 4s in bilayer MoS2. The 2p 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 2s state, the interlayer series remains optically visible up to 4s due to the hybridization with the intralayer B exciton. 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.