Optical absorption of a hydrogenic impurity in a disc-shaped quantum dot

Using the perturbation method and the effective-mass approximation, we studied a hydrogenic impurity confined in a disc-shaped quantum dot with a parabolic potential in the presence of an electric field. Both the electric field and the confinement effects on the transition energy and the oscillator strength were investigated. Based on the computed energies and wave functions, the linear, the third-order nonlinear and the total optical absorption coefficients were also calculated. The results show that the optical absorption coefficients obtained in a disc-shaped parabolic QD can reach the magnitude of 10(4)/cm, which is 1-2 orders of magnitude higher than that in the case of a spherical parabolic QD. We found that the transition energy, the oscillator strength, the linear, the third-order nonlinear and the total optical absorptions of the hydrogenic impurity in a disc-shaped QD dependent strongly on the confinement strength, and the applied electric field intensity. (c) 2009 Elsevier B.V. All rights reserved.