  Moir\'e superlattices in twisted van der Waals materials constitute a
promising platform for engineering electronic and optical properties. However,
a major obstacle to fully understanding these systems and harnessing their
potential is the limited ability to correlate the local moir\'e structure with
optical properties. By using a recently developed scanning electron microscopy
technique to image twisted WSe$_2$/WSe$_2$ bilayers, we directly correlate
increasing moir\'e periodicity with the emergence of two distinct exciton
species. These can be tuned individually through electrostatic gating, and
feature different valley coherence properties. Our observations can be
understood as resulting from an array of two intralayer exciton species
residing in alternating locations in the superlattice, and illuminate the
influence of the moir\'e potential on lateral exciton motion. They open up new
avenues for controlling exciton arrays in twisted TMDs, with applications in
quantum optoelectronics and explorations of novel many body systems.

Mesoscale and Nanoscale Physics