Effects of electric field and size on the electron-phonon interaction in a spherical quantum dot with impurity

• Published in: The European physical journal. B, Condensed matter physics Condensed matter physics, 2013-06, Vol.86 (6), Article 244
• Main Authors: Shi, Lei, Yan, Zu Wei
• Format: Article
• Language: English
• Subjects: Complex Systems; Condensed Matter Physics; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Fluid- and Aerodynamics; Lattice dynamics; Phonons in low-dimensional structures and small particles; Physics; Physics and Astronomy; Regular Article; Solid State Physics
• ISSN: 1434-6028; 1434-6036
• DOI: 10.1140/epjb/e2013-31061-1

The effects of electric field and size on the electron-phonon interaction with an on-center impurity in a Zn 1− x Cd x Se/ZnSe spherical quantum dot are studied, taking into account the interactions with confined, half-space and surface optical phonons. In addition, the interaction between impurity and phonons has also been considered. The results show that the electron-confined, electron-half-space, and electron-surface optical phonon interaction energies are all negative. The electron-confined optical phonon interaction energy is weakened by the electric field, but the electron-half-space and electron-surface optical phonon interaction energies are strengthened by it. In particular, the electron-surface optical phonon interaction depends strongly on the electric field, and it will vanish when the electric field is absent. It is also found that the electron-confined optical phonon interaction and electron-impurity “exchange” interaction energies reach a peak values as the quantum dot radius increases and then gradually decrease, but the electron-half-space optical phonon interaction energy exponentially quickly approaches 0 as the quantum dot radius increases.