  Halide perovskites are promising materials for light-emitting and
light-harvesting applications. In this context, two-dimensional perovskites
such as nanoplatelets or Ruddlesden-Popper and Dion-Jacobson layered structures
are important because of their structural flexibility, electronic confinement,
and better stability. This review article brings forth an extensive overview of
the recent developments of two-dimensional halide perovskites both in the
colloidal and non-colloidal forms. We outline the strategy to synthesize and
control the shape and discuss different crystalline phases and optoelectronic
properties. We review the applications of two-dimensional perovskites in solar
cells, light-emitting diodes, lasers, photodetectors, and photocatalysis.
Besides, we also emphasize the moisture, thermal, and photostability of these
materials in comparison to their three-dimensional analogs.
