  The optical spectrum of a quantum dot is typically dominated by the
fundamental transition between the lowest-energy configurations. However, the
radiative Auger process can result in additional red-shifted emission lines.
The origin of these lines is a combination of Coulomb interaction and
symmetry-breaking in the quantum dot. In this paper, we present measurements of
such radiative Auger lines for a range of InGaAs/GaAs self-assembled quantum
dots and use a tight-binding model with a configuration interaction approach to
explain their appearance. Introducing a composition fluctuation cluster in the
dot, our calculations show excellent agreement with measurements. We relate our
findings to group theory explaining the origin of the additional emission
lines. Our model and results give insight into the interplay between the
symmetry breaking in a quantum dot and the position and strength of the
radiative Auger lines.
