A particularly promising approach to realize optoelectronic devices based on semiconductor nanostructures are quantum dots coupled to an optical microcavity. Those quantum dot based light emitters are ideal sources for deterministic quantum light emission with tunable photon statistics. This paper investigates the theory of InAs/GaAs quantum dots (QDs) embedded in a two dimensional wetting layer (WL).To simulate realistic operating points for devices, the interactions between electrons and holes confined in the QDs and the wetting layer must be taken into account. Coulomb interaction in the emission process as well as electron-phonon coupling are included, considering multi-phonon processes based on an effective multiphonon Hamilton operator to calculate the quantum light emission on a microscopical level. The dynamics at low carrier densities, e. g. single photon emitter limit, is studied.