Probing Moiré Excitons in MoSe₂/WSe₂ Heterobilayers by Combined Micro-photoluminescence and Lateral Force Microscopy

We study interlayer excitons in MoSe₂/WSe₂ heterobilayers by combining lateral force microscopy and micro-photoluminescence spectroscopy. This allows us to correlate the spatial profile of the moiré superlattice with the distribution of optically active states accessible to interlayer excitons. In heterostructures where a twist angle of a few degrees is imposed between the MoSe₂ and WSe₂ crystallographic axes, we show that a continuous moiré lattice is realized across areas close to the optical diffraction limit. In such regions, the photoluminescence reduces to a few narrow-band lines only, energetically distributed consistently with the geometry of the moiré lattice. This correlation reveals that interlayer excitons explore a controlled periodic confinement, paving the way toward implementations of Bose-Hubbard models.