Thin film deposition and characterization of pure and iron-doped electron-beam evaporated tungsten oxide for gas sensors


Autoria(s): Tesfamichael, Tuquabo; Arita, Masashi; Bostrom, Thor E.; Bell, John M.
Data(s)

2010

Resumo

Pure Tungsten Oxide (WO3) and Iron-doped (10 at%) Tungsten Oxide (WO3:Fe) nanostructured thin films were prepared using a dual crucible Electron Beam Evaporation techniques. The films were deposited at room temperature in high vacuum condition on glass substrate and post-heat treated at 300 oC for 1 hour. From the study of X-ray diffraction and Raman the characteristics of the as-deposited WO3 and WO3:Fe films indicated non-crystalline nature. The surface roughness of all the films showed in the order of 2.5 nm as observed using Atomic Force Microscopy (AFM). X-Ray Photoelectron Spectroscopy (XPS) analysis revealed tungsten oxide films with stoichiometry close to WO3. The addition of Fe to WO3 produced a smaller particle size and lower porosity as observed using Transmission Electron Microscopy (TEM). A slight difference in optical band gap energies of 3.22 eV and 3.12 eV were found between the as-deposited WO3 and WO3:Fe films, respectively. However, the difference in the band gap energies of the annealed films were significantly higher having values of 3.12 eV and 2.61 eV for the WO3 and WO3:Fe films, respectively. The heat treated samples were investigated for gas sensing applications using noise spectroscopy and doping of Fe to WO3 reduced the sensitivity to certain gasses. Detailed study of the WO3 and WO3:Fe films gas sensing properties is the subject of another paper.

Formato

application/pdf

Identificador

http://eprints.qut.edu.au/31220/

Publicador

Elsevier

Relação

http://eprints.qut.edu.au/31220/3/41569.pdf

DOI:10.1016/j.tsf.2010.01.037

Tesfamichael, Tuquabo, Arita, Masashi, Bostrom, Thor E., & Bell, John M. (2010) Thin film deposition and characterization of pure and iron-doped electron-beam evaporated tungsten oxide for gas sensors. Thin Solid Films, 518(17), pp. 4791-4797.

Direitos

Copyright 2010 Elsevier

This is the author’s version of a work that was accepted for publication in <Thin Solid Films>. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Thin Solid Films, [VOL 518, ISSUE 17, (2011)] DOI: 10.1016/j.tsf.2010.01.037

Fonte

Faculty of Built Environment and Engineering; Faculty of Science and Technology; School of Engineering Systems

Palavras-Chave #020406 Surfaces and Structural Properties of Condensed Matter #100708 Nanomaterials #020499 Condensed Matter Physics not elsewhere classified #Tungsten Oxide #Electron Beam Evaporation #Co-evaporated Thin Films #Surface Morphology #Optical Properties #Surface Characterization #X-ray Photelectron Spectroscopy #Atomic Force Microscopy
Tipo

Journal Article