Optical studies of an exciton and a biexciton in a CdTe/ZnTe quantum dot nanostructure

Abstract

Electronic and some optical properties of exciton and biexciton in a CdTe/ZnTe quantum dot nanostructure are dealt taking into consideration of geometrical confinement effect. The binding energies, optical transition energies, recombination of oscillator strength, radiative life time and the absorption coefficients are carried out. Numerical calculations are performed using Hartree potential in order to obtain the Coulomb interaction energy and self-consistent technique is used to calculate the energy eigenvalue and wave functions of exciton and the biexciton. The electron and hole potentials are calculated from the Poisson equation. The dielectric mismatch on the electronic and optical properties is taken into account throughout the calculations. The linear and the nonlinear optical absorption coefficients for the heavy hole exciton and the biexciton as a function of incident photon energy for CdTe/ZnTe quantum dot are discussed. The results show that the electronic and optical properties strongly depend on the incident photon energy, recombination life time and the geometrical confinement.