Evidence for moire intralayer excitons in twisted WSe2/WSe2 homobilayer superlattices

Recent advances in twisted van der Waals heterostructure superlattices have emerged as a powerful and attractive platform for exploring novel condensed matter physics due to the interplay between the moire potential and Coulomb interactions. The moire superlattices act as a periodic confinement potential in space to capture interlayer excitons (IXs), resulting in moire exciton arrays, which provide opportunities for quantum emitters and many-body physics. The observation of moire IXs in twisted transition-metal dichalcogenide (TMD) heterostructures has recently been widely reported. However, the capture and study of the moire intralayer excitons based on TMD twisted homobilayer (T-HB) remain elusive. Here, we report the observation of moire intralayer excitons in a WSe2/WSe2 T-HB with a small twist angle by measuring PL spectrum. The multiple split peaks with an energy range of 1.55-1.73 eV are different from that of the monolayer WSe2 exciton peaks. The split peaks were caused by the trapping of intralayer excitons via the moire potential. The confinement effect of the moire potential on the moire intralayer excitons was further demonstrated by the changing of temperature, laser power, and valley polarization. Our findings provide a new avenue for exploring new correlated quantum phenomena and their applications.