Photoionization cross section and refractive-index change of hydrogenic impurities in a CdS-SiO2 spherical quantum dot


YILMAZ S. , Safak H., ŞAHİNGÖZ R. , Erol M.

CENTRAL EUROPEAN JOURNAL OF PHYSICS, vol.8, no.3, pp.438-444, 2010 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 3
  • Publication Date: 2010
  • Doi Number: 10.2478/s11534-009-0115-8
  • Title of Journal : CENTRAL EUROPEAN JOURNAL OF PHYSICS
  • Page Numbers: pp.438-444

Abstract

In this study, we calculate the photoionization cross section and refractive-index change of an on-center hydrogenic impurity in a CdS-SiO2 spherical quantum dot. In numerical calculations, both the finite- and infinite-confinement cases are considered and a variational scheme is adopted to determine the energy eigenvalues for the impurity. The variations of the photoionization cross section with the dot radius, the refractive-index change, and the normalized photon energy are investigated, and the effect of the potential-barrier height on the cross section is discussed. The results obtained show that the photoionization cross section and the refractive-index change in CdS-SiO2 spherical quantum dots are sensitively dependent on the incident optical intensity and on the dot sizes.