Mode assignment of excited states in self-assembled InAs/GaAs quantum dots

The modes of excited states of electrons and holes in self-assembled InAs/GaAs quantum dots (QD’s) are investigated through photoluminescence (PL) and photoluminescence excitation (PLE) polarization properties with the aid of the theoretical calculation. First, the wave functions of electrons and holes are calculated by solving the three-dimensional Schrödinger equation using the finite element method by considering the effect of the strain distributions inside and/or around QD’s. It is shown that there exist excited states of not only holes but also electrons in [11¯0] and [110] directions. Based on the results, the polarization properties of transitions between excited states of electrons and holes with the same quantum numbers are calculated. Then, the PL and PLE polarization properties are measured, and the modes of the excited states are assigned by comparing the calculation results.