Electronic states and oscillator strengths for interband transitions of a graded quantum dot quantum well structure

A theoretical study of electron and hole electronic states and oscillator strength of interband transitions in a graded spherical HgS/CdS/HgS/CdS quantum dot quantum well (QDQW) nanostructure is presented; also the Coulomb interaction energies of excitons are calculated. The Finite Element Method (FEM) is used for solving the problem with the position dependent effective mass approximation. The results of calculations show that gradation of the potential decreases energies of confined particles and considerably reduces the oscillator strength for certain transitions. The gradation of the potential can be used as an additional parameter for experimental purposes to manipulate needed properties of the QDQW structure.