  Hexagonal boron nitride (hBN) is a wide bandgap van der Waals material that
has recently emerged as promising platform for quantum photonics experiments.
In this work we study the formation and localization of narrowband quantum
emitters in large flakes (up to tens of microns wide) of hBN. The emitters can
be activated in as-grown hBN by electron irradiation or high temperature
annealing, and the emitter formation probability can be increased by ion
implantation or focused laser irradiation of the as-grown material.
Interestingly, we show that the emitters are always localized at edges of the
flakes, unlike most luminescent point defects in 3D materials. Our results
constitute an important step on the road map of deploying hBN in nanophotonics
applications.
