Electronic and optical properties of a D2+ complex in two-dimensional quantum dots with Gaussian confinement potential

Using the two-dimensional diagonalization method and the effective mass approximation, the electronic structure and intersubband optical absorption of the singly ionized double donor complex confined in a Gaussian quantum dot have been investigated. The obtained results indicated that the quantum dot size and internuclear distance significantly affect the binding energy, dissociation energy, equilibrium distance, and amplitude of the optical absorption. Also, we conclude that a significant increase in the amplitude of the dipole-related matrix element and the energy difference between the two lowest-lying energy states is observed when the distance between the donor atoms is in the order of the quantum dot size. Consequently, the electronic and optical properties can be precisely tuned by controlling the system's size and the internuclear distance.