  A crucial requirement for the realisation of efficient and scalable on-chip
quantum communication is an ultrafast polarised single photon source operating
beyond the Peltier cooling barrier of 200 K. While a few systems based on
different materials and device structures have achieved single photon
generation above this threshold, there has been no report of single quantum
emitters with deterministic polarisation properties at the same high
temperature conditions. Here, we report the first device to simultaneously
achieve single photon emission with a g(2)(0) of only 0.21, a high polarisation
degree of 0.80, a fixed polarisation axis determined by the underlying
crystallography, and a GHz repetition rate with a radiative lifetime of 357 ps
at 220 K. The temperature insensitivity of these properties, together with the
simple planar growth method, and absence of complex device geometries, makes
this system an excellent candidate for on-chip applications in integrated
systems.
