Electronic and optical properties of non-uniformly shaped InAs/InP quantum dashes

We theoretically study the optical properties and the electronic structure of highly elongated InAs/InP quantum dots (quantum dashes) and show how carrier trapping due to geometrical fluctuations of the confining potential affects the excitonic spectrum of the system. We focus on the study of the optical properties of a single exciton confined in the structure. The dependence of the absorption and emission intensities on the geometrical properties (size and position) of the trapping centre within the quantum dash is analysed and the dependence of the degree of linear polarization on these geometrical parameters is studied in detail. The role of Coulomb correlations for the optical properties of these structures is clarified. (paper)