Energy spectrum of the impurity molecular $A^+_2$-ion in the spherically symmetric quantum dot

The work aims at theoretical study of influence of the exchange interaction associated with a change in spatial configuration of the molecular ion in volume of the spherically symmetric quantum dot on the terms and the energy spectrum of $A^+_2$-center. Numerical analysis of the dispersion equations has been made for the case of the quantum dot, based on InSb. The method of the zero-range potential and the effective mass approximation have been used for calculation of the energy spectrum for $A^+_2$-center in the quantum dot, described by the model of “rigid” walls. The authors have investigated the influence effect of the exchange interaction, initiated by the change in the spatial configuration for the $A^+_2$-center in volume of the quantum dot, to the position of the g- and u-terms of the impurity molecular ion. It is shown that with the increase of the exchange interaction the splitting between terms is also increased and the binding energy of g- and u-states for $A^+_2$-center considerably changes. The exchange interaction between $A^+_2$-centers in the molecular ion can lead to the essential modification of g- and u-terms for the $A^+_2$-center, and as a consequence, to change in the photoluminescence peak position associated with the radiative transition of the photoexcited electron to g-state of the $A^+_2$-center.