Electronic states and optical properties of single donor in GaN conical quantum dot with spherical edge. (February 2018)

• Record Type: Journal Article
• Authors: El Aouami, A.; Feddi, E.; El-Yadri, M.; Aghoutane, N.; Dujardin, F.; Duque, C.A.; Phuc, Huynh Vinh
• Is Part Of: Superlattices and microstructures. Volume 114(2018)
• Page Start: 214
• Page End: 224
• Publication Date: 2018-02
• Subjects: Conical dot -- Donor impurity -- Binding energy -- Photoionization cross-section -- Absorption coefficient; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.12.043
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: In this paper we present a theoretical investigation of quantum confinement effects on the electron and single donor states in G a N conical quantum dot with spherical edge. In the framework of the effective mass approximation, the Schrödinger equations of electron and donor have been solved analytically in an infinite potential barrier model. Our calculations show that the energies of electron and donor impurity are affected by the two characteristic parameters of the structure which are the angle Ω and the radial dimension R . We show that, despite the fact that the reduction of the two parameters Ω and R leads to the same confinement effects, the energy remains very sensitive to the variation of the radial part than the variation of the angular part. The analysis of the photoionization cross-section corresponding to optical transitions between the conduction band and the first donor energy level shows clearly that the reduction of the radius R causes a shift in resonance peaks towards the high energies. On the other hand, the optical transitions between 1 s − 1 p, 1 p − 1 d and 1 p − 2 s show that the increment of the conical aperture Ω (or reduction of R ) implies a displacement of the excitation energy to higher energies. Highlights: Electron and single donor states in GaN conical quantum dot. Effective mass approximation with analytical solutions. Photoionization cross-section for impurity-electron transitions. Optical transitions are blue/red shifted with geometry variations.