  Moir\'e superlattices have emerged as a new platform for studying strongly
correlated quantum phenomena, but these systems have been largely limited to
van der Waals layer two-dimensional (2D) materials. Here we introduce moir\'e
superlattices leveraging ultra-thin, ligand-free halide perovskites,
facilitated by ionic interactions. Square moir\'e superlattices with varying
periodic lengths are clearly visualized through high-resolution transmission
electron microscopy. Twist-angle-dependent transient photoluminescence
microscopy and electrical characterizations indicate the emergence of localized
bright excitons and trapped charge carriers near a twist angle of ~10{\deg}.
The localized excitons are accompanied by enhanced exciton emission, attributed
to an increased oscillator strength by a theoretically forecasted flat band.
This work illustrates the potential of extended ionic interaction in realizing
moir\'e physics at room temperature, broadening the horizon for future
investigations.
