Interband optical absorption in a strained Cd sub(xZn) sub(1)-xO/ZnO quantum dot

Numerical calculations of the excitonic absorption spectra in a strained Cd sub(xZn) sub(1)-xO/ZnO quantum dot are investigated for various Cd contents. We calculate the quantized energies of the exciton as a function of dot radius for various confinement potentials and thereby the interband emissio...

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Bibliographic Details
Published in:Physica. B, Condensed matter Condensed matter, 2011-10, Vol.406 (19), p.3666-3670
Main Authors: Peter, AJohn, Lee, Chang Woo
Format: Article
Language:English
Subjects:
Absorption spectra
Cadmium
Confinement
Excitation
Excitation spectra
Mathematical analysis
Mathematical models
Qunatum dots
Zinc oxide
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Summary:Numerical calculations of the excitonic absorption spectra in a strained Cd sub(xZn) sub(1)-xO/ZnO quantum dot are investigated for various Cd contents. We calculate the quantized energies of the exciton as a function of dot radius for various confinement potentials and thereby the interband emission energy is computed considering the internal electric field induced by the spontaneous and piezoelectric polarizations. The optical absorption as a function of photon energy for different dot radii is discussed. Decrease of exciton binding energy and the corresponding optical band gap with the Cd concentration imply that the confinement of carriers decreases with composition x. The main results show that the confined energies and the transition energies between the excited levels are significant for smaller dots. Non-linearity band gap with the increase in Cd content is observed for smaller dots in the strong confinement region and the magnitude of the absorption spectra increases for the transitions between the higher excited levels.
ISSN:0921-4526
DOI:10.1016/j.physb.2011.06.067