Temperature-Dependent Optical Properties of InAs/GaAs Self-Assembled Quantum Dots: Spectroscopic Measurements and an Eight-Band Study

The temperature-dependent optical properties of InAs/GaAs self-assembled quantum dots are studied by spectroscopic measurements along with the corresponding theoretical calculations. We observe the redshift of photoluminescence peak energy with increasing temperature and the thermally activated quenching of each state, which result from the efficient redistribution of carriers in quantum dots. Meanwhile, the electronic structures of the InAs/GaAs quantum dots are investigated by a detailed theoretical study in terms of an eight-band k⋅p model, taking strain effects into account. The calculated transition energies of the excitons are in reasonable agreement with the results of the photoluminescence spectra. According to the spatial distribution of carriers, it is found that the evolution of photogenerated excitons in quantum dots with temperature mainly relies on the electrons rather than the holes.