Excitons In The Quantum Dot Quantum Well Structure

Within the framework of dielectric continuum approximation and the effective mass approximation, the exciton and the exciton-phonon interaction in quantum dot quantum well (QDQW) structure are studied theoretically by using variational method. The effect of the quantum confinement is described by both infinite and finite potential well, the results obtained are generalized as follows:1. We studied the exciton-phonon interaction in a spherical QDQW structure with the infinite value of the quantum confinement potential. The effect of the longitudinal optical phonons and the surface optical phonons are taken into account. The results show that the ground-state energy of the exciton with and without phonon interaction increases monotonously with increasing the core radius. The energy contribution of phonon decreases with increasing the core radius. The binding energy of the exciton with and without phonon interaction decreases monotonously with increasing the shell thickness. The polaronic effect on the binding energy increases monotonously with increasing the shell thickness.2. We studied the exciton in a spherical QDQW structure with the finite value of the quantum confinement potential. The results show that the ground-state energy and the binding energy of the exciton decreases monotonously with increasing the shell thickness.The results indicate that the quantum confinement effects of a QDQW structure is predominant.