Localized excitons in a proximitized moiré lattice*

We report the observation of localized excitons in a monolayer MoSe2 when placed in the proximity of a moiré lattice formed via twisted hBN layers. When hBN is twisted with a small angle, it forms a moiré pattern with alternating potential domains at the interface. This potential difference can be used to control the properties of excitons located on the surface of the hBN. We demonstrate this effect by placing a monolayer of MoSe2 on the twisted hBN with varying twist angles. The presence of the underlying moiré potential results in the photoluminescence of excitons in MoSe2 blue shifting indicative of confinement effect. Using a Kelvin probe force microscope(KPFM), we observed potential modulation on the MoSe2 of ~ 40 meV at 4K.