  Hereby, we present a comprehensive experimental and theoretical study of the
electronic structure and optical properties of excitonic complexes in
strain-engineered InGaAs/GaAs quantum dots (QDs) grown by metal-organic
chemical vapour deposition and emitting at the 1300 nm telecommunication
window. Single QD properties have been determined experimentally for a number
of nanostructures by means of excitation-power-dependent and
polarization-resolved microphotoluminescence and further compared with the
results of confined states calculations employing the 8-band kp theory combined
with the configuration interaction method. The origin of excitonic complexes
has been exemplarily confirmed based on magnetooptical and correlation
spectroscopy study. Understanding the influence of structural parameters and
compositions (of QDs themselves as well as in the neighbouring strain reducing
layer) allows to distinguish which of them are crucial to control the emission
wavelength to achieve the telecommunication spectral range or to affect binding
energies of the fundamental excitonic complexes. The obtained results provide
deeper knowledge on control and on limitations of the investigated structures
in terms of good spectral isolation of individual optical transitions and the
spatial confinement that are crucial in view of QD applications in
single-photon sources of high purity at telecom wavelengths.
