Self-consistent computation of electronic and optical properties of a single exciton in a spherical quantum dot via matrix diagonalization method

Abstract

Cataloged from PDF version of article.In this study, we develop and demonstrate an efficient self-consistent calculation schema that computes the electronic structure and optical properties of a single exciton in a spherical quantum dot (QD) with an interacting pair of electron and hole wave functions. To observe modifications on bands, wave functions, and energies due to the attractive Coulomb potential, the full numeric matrix diagonalization technique is employed to determine sublevel energy eigenvalues and their wave functions in effective mass approximation. This treatment allows to observe that the conduction and valance band edges bend, that the electron and hole wave functions strongly localize in the QD, and that the excitonic energy level exhibits redshift. In our approach for the Coulomb term between electron and hole, the Poisson-Schrodinger equations are solved self-consistently in the Hartree approximation. Subsequently, exciton binding energies and associated optical properties are computed. The results are presented as a function of QD radii and photon energies. We conclude that all of these numerical results are in agreement with the experimental studies. (C) 2009 American Institute of Physics

Wavefunction Engineering of Type-I/Type-II Excitons of CdSe/CdS Core-Shell Quantum Dots

“…Similarly, for the hole (eq. 6), it is calculated by reducing confinement potential of electrons with the difference of band gap between core and shell 33 . Beyond R 2 , the QD is assumed to be in an infinite potential wall, this amounts to a node for the electron and hole wavefunctions at the periphery of the spherical QD.…”

“…Equations 9 and 10 models the electronic potential images which arise due to surface polarization at the core-shell boundaries. The charge carriers (e–h) linear densities are as follows 33 :Here, n represents the principal quantum number and l is the azimuthal quantum number. Since we are concerned with the modelling of s-s transitions for the excitations, therefore we have assumed n = 1 and l = 0 for both the electron as well as a hole.…”

Quantum dot and electron acceptor nano-heterojunction for photo-induced capacitive charge-transfer

“…To investigate the electronic properties of the QDs in detail, we conducted quantum mechanical calculations by solving self-consistently the Poisson–Schrödinger equations in the effective mass approximation and using BenDaniel–Duke boundary conditions 29 . The material parameters used in the calculations are listed in Table 1 .…”

“…The material parameters used in the calculations are listed in Table 1 . All Coulombic interactions have been taken into account on both energy eigenvalues and wavefunctions 29 . At the end of the calculations, single particle energies of electron and hole and corresponding radial wavefunctions have been determined.…”

The intersubband optical properties of a two-electron quantum dot-quantum well heterostructure

“…The material parameters are m * CdSe = 0.13m 0 and m * ZnS = 0.28m 0 , κ CdSe = 9.3 and κ ZnS = 8.1, n r = 2.6, the electron confinement potential is V b = 1.05 eV [38]. Here, the Lorentzian peak width is chosen as Γ ab = 3.28 meV.…”