Fulltext

UV Absorptance of Titanium Dioxide Thin Films by Plasma Enhanced Deposition from Mixtures of Oxygen and Titanium-Tetrakis-Isopropoxide

Sonnenfeld, Axel ; von Sonnenfeld, Philipp ; Hauert, Roland

In: Plasma Chemistry and Plasma Processing, 2006, vol. 26, no. 3, p. 319-334

Ajouter à la liste personnelle
    Titre
    • UV Absorptance of Titanium Dioxide Thin Films by Plasma Enhanced Deposition from Mixtures of Oxygen and Titanium-Tetrakis-Isopropoxide
    Auteur
    • Sonnenfeld, Axel. Institute of Process Engineering, ETH Zurich, CH-8092, Zurich, Switzerland
    • von Sonnenfeld, Philipp. Institute of Process Engineering, ETH Zurich, CH-8092, Zurich, Switzerland
    • Hauert, Roland. Empa, Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Plasma Chemistry and Plasma Processing, 2006, vol. 26, no. 3, p. 319-334. Springer US; http://www.springer-ny.com
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:310740
    Summary
    A low pressure radio frequency discharge was used to deposit films by mixtures of oxygen and titanium (IV) isopropoxide (TTIP) at powers of 200W on films of polyethylene-terephthalat and samples of quartz glass. In the non-thermal plasma, films of rather pure TiO2 could be deposited as revealed by X-ray photo-electron spectroscopy. Besides the film growth rate and the chemical composition, the spectral behaviour of the spectral transmittance of visually transparent films was determined in the range from 200 to 500nm. Furthermore, the absorptance of films has been derived at characteristic spectral positions of the transmission spectra of the films. Accordingly, cut-off wavelength was found to increase with deposition time from 5 to 10min as well as with the concentration of TTIP in a range below 1.7%. At 310nm, the spectral absorption coefficient (extinction coefficient × concentration) was 12μm−1. While keeping other parameters constant, this coefficient decreased by 4μm−1 due to an increase of the concentration of TTIP from 1.7% to 8%. Simultaneously, the surface roughness increased as revealed by profilometry. Thus, since the chemical structure of films was found to change only marginally, a decrease of the film density is likely to cause the observed dependence of the absorption coefficient with increasing precursor concentration