Excitonic states in spherical layered quantum dots

Abstract

he properties of excitons formed in spherical quantum dots are studied using the $\mathbf{k}\cdot \mathbf{p}$ method within the Hartree approximation. The spherical quantum dots considered have a central core and several concentric layers of different semiconductor materials that are modeled as a succession of potential wells and barriers. The $\mathbf{k}\cdot \mathbf{p}$ Hamiltonian and the Coulomb equations for the electron-hole pair are solved using a self-consistent iterative method. The calculation of the spectrum of the empty quantum dot and the electron-hole pair is performed by means of a very accurate numerical approximation. It is found that the exciton binding energy as a function of the core radius of the quantum dot shows a strong non-linear behaviour. In particular, for quantum dots with two potential wells, the binding energy presents a large steep change. This last behaviour is explained in terms of the polarization charges at the interfaces between different materials and the matching conditions for the eigenfunctions.

References in corpus (3)

• Interrelation of structural and electronic properties of InGaN/GaN quantum dots using an eight-band k.p model
• Recent advances in exciton based quantum information processing in quantum dot nanostructures
• Stark Effect of Interactive Electron-hole pairs in Spherical Semiconductor Quantum Dots

Cited by in corpus (2)

• Characterization of helical states in semiconductor quantum wells using quantum information quantities
• Study of the transition from resonance to bound states in quantum dots embedded on a nanowire using the $\mathbf{k}\cdot \mathbf{p}$ method