Excitons in inhomogeneous quantum dots

The properties of excitons in inhomogeneous quantum dots have been theoretically studied in the strong confinement regime; these dots have an internal structure, with an inner core that behaves as a repulsive potential for electrons and holes. The model includes a rigorous (macroscopic) treatment of the dielectric mismatch at the dot boundaries. Analytical (numerical) results are obtained for the ground- (excited-) state exciton. It is found in all cases that the exciton binding energy decreases by increasing the size of the core region; on the other hand, the dielectric enhancement of the exciton binding energy becomes even more pronounced than in homogeneous quantum dots. [S0163-1829(98)02815-X].