  The features of some potential single-photon sources in two-dimensional
silicon carbide monolayers is studied via ab-initio calculation and group
theory analysis. A few point defects in three charge states (negative, positive
and neutral) are considered. By applying performance criteria, Stone-Wales
defects without and with combination of antisite defects are studied in
details. The formation energy calculations reveal that neutral and positive
charge states of these defects are stable. We compute the zero-phonon-line
energy, the Huang-Rhys (HR) factor and the photoluminescence spectrum for the
available transitions in different charge states. The calculated HR values and
the related Debye-Waller factors guarantee that the Stone-Wales defects have a
high potential of performing as a promising single-photon emitter.
