Non-delta-function electronic spectral densities in individual quantum dots

Using a simplified model approach we estimate the optical line shape of the transition lines observable in photoluminescence experiments on quantum dots. We use the theory based on the interaction of electrons with the longitudinal optical phonons only. This theory gives, in the self-consistent Born approximation, the lowest-energy excited state line shape in the form of a very narrow peak with a shoulder on the low-energy side. We turn the attention to a comparison with experiments which appear to support this theoretical conclusion. This agreement emphasizes the role of the electronic multiple scattering on optical phonons in quantum dots. It is demonstrated that the optical line shape can give an information about the quantum dot system.