Twist Angle-Dependent Interlayer Exciton in MoS₂ Bilayers Revealed by Room-Temperature Reflectance

In 2H stacking bilayer MoS₂, the exciton with an interlayer nature has been evidenced due to the hybridization of hole states among both layers. The transition energy of this interlayer exciton is located between the A and B excitons. In this work, we investigate the evolution of optical properties in stacking MoS₂ bilayers with the twisted angles ranging from 0^◦ to 60^◦, especially focusing on the interlayer exciton. The clear modulations of the exciton responses are observed by the room-temperature reflectance. The interlayer exciton transition is observed in the artificial stacking bilayer MoS₂ with the twisted angle around 60^◦ . We found that the interlayer exciton is very sensitive to the twisted angle. Once the stacking angle deviates the 2H stacking by a few degrees, the interlayer transition is quenched. This is due to the bilayer symmetry and interlayer coupling of this unique system.