  Hexagonal boron nitride is rapidly gaining interest as a platform for
photonic quantum technologies, due to its two-dimensional nature and its
ability to host defects deep within its large band gap that may act as
room-temperature single-photon emitters. In this review paper we provide an
overview of (1) the structure, properties, growth and transfer of hexagonal
boron nitride; (2) the creation and assignment of colour centres in hexagonal
boron nitride for applications in photonic quantum technologies; and (3)
heterostructure devices for the electrical tuning and charge control of colour
centres that form the basis for photonic quantum technology devices. The aim of
this review is to provide readers a summary of progress in both defect
engineering and device fabrication in hexagonal boron nitride based photonic
quantum technologies.
