Shallow donor inside core/shell spherical nanodot: Effect of nanostructure size and dielectric environment on energy spectrum. (November 2017)

• Record Type: Journal Article
• Authors: Chafai, A.; Dujardin, F.; Essaoudi, I.; Ainane, A.; Ahuja, R.
• Is Part Of: Superlattices and microstructures. Volume 111(2017)
• Page Start: 976
• Page End: 982
• Publication Date: 2017-11
• Subjects: Shallow donor -- Core/shell materials -- Nanostructures -- Quantum dots; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.07.063
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: We have reported the impact of the core and shell radii on the energy spectrum of centered shallow donor confined inside CdSe/ZnTe core/shell quantum dot and ZnTe/CdSe inverted core/shell quantum dot. The dielectric discontinuity between the nanosystems and their surrounding medium was considered. In order to examine the behavior of the donor binding energy as a function of the spatial parameters a variational approach within the framework of the effective-mass approximation was deployed. Our model shows that for a fixed shell radius the increase of the core radius value blue-shifts the binding energy of the donor inside inverted core/shell quantum dot only if the value of the core to shell radii ratio is between 0.9 and 1, otherwise it is red-shifted. By contrast, for core/shell quantum dot system the binding energy is red-shifted by increasing the core radius for a fixed nanostructure size and for all values of the core to shell radii ratio. We have also found that the donor binding energy values are more important in a core/shell nanodot than in an inverted core/shell quantum dot. Highlights: Theoretical model of a centered donor in core/shell nanodots. Comparison between CdSe/ZnTe and ZnTe/CdSe structures. Influence of the core/shell sizes and of the external dielectric constant on the binding energy.