Table of Contents
ISRN Condensed Matter Physics
Volume 2012, Article ID 738023, 10 pages
http://dx.doi.org/10.5402/2012/738023
Research Article

Quantum Effects of Indium/Ytterbium Doping on ZnO-Like Nano-Condensed Matter in terms of Urbach-Martienssen and Wemple-DiDomenico Single-Oscillator Models Parameters

1Unité de Physique des Dispositifs à Semi-Conducteurs, Faculté des Sciences Mathematiques, Physiques et Naturelles de Tunis, Université de Tunis El Manar, 2092 Tunis, Tunisia
2Département de Physique et Chimie, École Supérieure des Science et Techniques de Tunis, Université de Tunis, 1007 Tunis, Tunisia
3Unité de Recherche MA2I, Ecole Nationale d'Ingénieurs de Tunis (ENIT), BP 37, Le Belvédère, 1022 Tunis, Tunisia

Received 22 November 2011; Accepted 2 January 2012

Academic Editors: A. Krimmel and S. Krukowski

Copyright © 2012 A. Boukhachem et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Conducting and transparent optical ZnO thin films were deposited on glass substrates by a simple mini spray technique. Alternatively, some of the obtained films were doped with indium and ytterbium at the molar rates of: 1, 2, and 3% (In) and 100, 200, and 300 ppm (Yb). In addition to the classical structural investigations including XRD, microhardness vickers (Hv), and optothermal techniques, thorough optical measurements have been carried out for comparison purposes. The refractive indices and the extinction coefficients of the differently doped layers have been deduced from their transmission-reflection spectra over an extended wavelength range. Analysis of the refractive index data through Wemple-DiDomenico single oscillator model yielded quantum characteristics along with the values of long-wavelength dielectric constant, average oscillator wavelength, average oscillator strength, average oscillator energy and dispersion energy. Real and imaginary parts of dielectric constant have also been used to calculate free carrier plasma resonance frequency, optical relaxation time, and free carriers concentration-to-effective mass ratio. Finally, analysis of Urbach-Martienssen model parameters allowed proposing nanoscale explanations to the divergence about doping-related evolution of Urbach tails, this intriguing item having been intensively discussed in the literature in the last decades.