Аннотация:Single-photon sources are a fundamental element for developing quantum
technologies, and sources based on colour centres in diamonds are among the
most promising candidates. The well-known NV centres are characterized by
several limitations, thus few other defects have recently been considered. In
the present work, we characterize in detail native efficient single colour
centres emitting in the near infra-red in both standard IIa single-crystal and
electronic-grade polycrystalline commercial CVD diamond samples. In the former
case, a high-temperature annealing process in vacuum is necessary to induce the
formation/activation of luminescent centres with good emission properties,
while in the latter case the annealing process has marginal beneficial effects
on the number and performances of native centres in commercially available
samples. Although displaying significant variability in several photo physical
properties (emission wavelength, emission rate instabilities, saturation
behaviours), these centres generally display appealing photophysical properties
for applications as single photon sources: short lifetimes, high emission rates
and strongly polarized light. The native centres are tentatively attributed to
impurities incorporated in the diamond crystal during the CVD growth of
high-quality type IIa samples, and offer promising perspectives in
diamond-based photonics.