Modeling the optical properties of WO(3) and WO(3)-SiO(2) thin films


Saygin-Hinczewski D., Hinczewski M., Sorar I., Tepehan F. Z. , Tepehan G. G.

SOLAR ENERGY MATERIALS AND SOLAR CELLS, vol.92, no.8, pp.821-829, 2008 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 92 Issue: 8
  • Publication Date: 2008
  • Doi Number: 10.1016/j.solmat.2008.01.021
  • Title of Journal : SOLAR ENERGY MATERIALS AND SOLAR CELLS
  • Page Numbers: pp.821-829

Abstract

The optical properties and surface morphology of sol-gel spin coated WO(3) and WO(3)-SiO(2) composite films annealed at 250 and 400 degrees C are investigated. For the purpose of extracting the optical parameters of the films, a novel form for the dielectric function is introduced, consisting of two Tauc-Lorentz oscillators and an Urbach tail component, which is suited for amorphous multi-transition materials with substantial subgap absorption. The evolution of the refractive indices, transmittances, and band gaps with doping is marked by sizable shifts at 2.0-2.5% SiO(2) doping for the 250 degrees C films, and 4.0-4.5% doping for the 400 degrees C films. In addition, pronounced changes in the surface roughness of the films occur at these doping values. (c) 2008 Elsevier B.V. All rights reserved.