Binding energy of a quasi-molecule in nanoheterostructures

摘要

This paper shows that the appearance of a quasi-molecule consisting of two cadmium sulfide quantum dots located in a borosilicate glass matrix with electrons localized above the surfaces of the quantum dots has a threshold character and can occur in a nanosystem in which the distance D between the surfaces of the quantum dots is determined by the condition D-c((1)) <= D <= D-c(2) (where D-C((1)) and D-c((2)) are certain critical distances). A substantial increase (by more than an order of magnitude) is detected in the binding energy of the singlet ground state of a quasi-molecule by comparison with the binding energy of a biexciton in single-crystal cadmium sulfide. It is established that the main contribution to the binding energy of the quasi-molecule is from the electron-hole exchange-interaction energy, which is substantially greater than the contribution of the electron-hole Coulomb-interaction energy. (C) 2017 Optical Society of America.