Abstract
We present a detailed study of the morphology and composition of tungsten oxide (WO3) thin films, grown by radio frequency magnetron reactive sputtering at substrate temperatures varied from room temperature (RT) to 500 °C, using infrared (IR) absorption, Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS). This work includes valuable new far-IR results about structural changes in microcrystalline WO3. Both IR absorption and Raman techniques reveal an amorphous sample grown at RT and initial crystallization into monoclinic structures for samples grown at temperatures between 100 and 300 °C. The Raman spectra of the samples grown at high temperatures indicate, apart from the monoclinic structure, a strain effect, with a distribution revealed by confocal Raman mapping. XPS indicates that the film surface maintains the stoichiometry WOx, with a value of x slightly greater than 3 at RT due to oxygen contamination, which decreases with increasing temperature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A.I. Gavrilyuk, B.P. Zakharchenya, and F.A. Chudnovskii: Photo-chromism in WO3 thin films Electrochim. Acta 44, 3027 (1999).
S.K. Deb: Optical and photoelectric properties and color centers in thin films of WO3Philos. Mag. 17, 801 (1973).
C.S. Blackman and L.P. Parkin: Atmospheric pressure chemical vapor deposition of crystalline monoclinic WO3 and WO3_x thin films from reaction of WCl6 with O-containing solvents and their photochromic and electrochromic properties Chem. Mater. 17, 1583 (2005).
S.H. Lee, R. Deshpande, P.A. Parilla, K.M. Jones, B. To, A.H. Mahan, and A.C. Dillon: Crystalline WO3 nanoparticles for highly improved electrochromic applications Adv. Mater. 18, 763 (2006)
S.H. Baeck, K.S. Choi, T.F. Jaramillo, G.D. Stucky, and E.W. McFarland: Enhancement of photocatalytic and electro-chromic properties of electrochemically fabricated mesoporous WO3 thin films Adv. Mater. 15, 1269 (2003).
W. Cheng, E. Baudrin, B. Dunn, and J.I. Zink: Synthesis and electrochromic properties of mesoporous tungsten oxide J. Mater. Chem. 11, 92 (2001).
L. Zhou, Q. Ren, X. Zhou, J. Tang, Z. Chen, and C. Yu: Comprehensive understanding on the formation of highly ordered mesoporous tungsten oxides by x-ray diffraction and Raman spectroscopy Microporous Mesoporous Mater. 109, 248 (2008).
P.M.A. Durrani, E.E. Khawaja, M.A. Salim, M.F. Al-Kuhaili, and A.M. Al-Shukri: Effect of preparation conditions on the optical and fhermochromic properties of thin films of tungsten oxide Sol. Enemy Mater. Sol. Cells 71, 313 (2002).
S.H. Lee, K.M. Cheong, P. Liu, D. Smith, C.E. Tracy, A. Mascarenhas, J.R. Pitts, and S.K. Deb: Raman spectroscopic studies of gaso-chromic a-WO3 thin films Electrochim. Acta 46, 1995 (2001).
S.M. Kanan, O.M. El-Kadri, L.A. Abu-Yousef, and M.C. Kanan: Semiconducting metal oxide based sensors for selective gas pollutant detection Sensors 9, 8158 (2009).
D.E. Williams: Semiconducting oxides as gas-sensitive resistors Sens. Actuators. B 57, 1 (1999).
A. Kolmakov and M. Maskovits: Chemical sensing and catalysis by one-dimensional metal-oxide nanostructures Annu. Rev. Mater. Res. 34, 151 (2004).
W.H. Tao and C.H. Tsai: H2S sensing properties of noble metal doped WO3 thin film sensor fabricated by micromachining Sens. Actuators. B 81, 237 (2002).
M. Stankova, X. Vilanova, J. Calderer, E. Llobet, J. Brezmes, I. Gracia, C. Cane, and X. Correig: Sensitivity and selectivity improvement of RF sputtered WO3 microhotplate gas sensors Sens. Actuators. B 113, 241 (2006).
C.V. Ramana, S. Utsunomiya, R.C. Ewing, C.M. Julien, and U. Becker: Structural stability and phase transitions in WO3 thin films J. Phys. Chem. B 110, 10430 (2006).
E. Salje: The orfhorhombic phase of WO3Acta Crystallogr:, Sect. B: Struct Sci. 33, 574 (1977).
S. Tanisaki: Crystal structure of monoclinic tungsten trioxide at room temperature J. Phys. Soc. Jpn. 15, 573 (1960).
P.M. Woodward, A.W. Sleight, and T. Vogt: Ferroelectric tungsten trioxide J. Solid State Chem. 131, 9 (1997).
M. Boulova, N. Rosman, P. Bouvier, and G. Lucazeau: High-pressure Raman study of microcrystalline WO3 tungsten oxide J. Phys. Condens. Matter 14, 5849 (2002).
A.G. Souza Filho, P.T.C. Freire, O. Pilla, A.P. Ayala, J. Mendes Filho, P.E.A. Melo, V.N. Freire, and V. Lemos: Pressure effects in Raman spectrum of WO3 microcrystals Phys. Rev. B: Condens Matter 62, 3699 (2000).
E. Salje: Lattice dynamics of WO3Acta Crystallogr., Sect. A: Found Crvstalloer. 31, 360 (1975).
S.K. Gullapalli, F.S. Manciu, J.L. Enriquez, and C.V. Ramana: Tungsten oxide (WO3) thin films for application in advanced energy systems J. Vac. Sci. Technol. A 28, 824 (2010).
K. Ohwada: Lattice vibrations of 5-uranium and tungsten trioxides Spectrochim. Acta, Part A 26A, 1035 (1969).
B. Pecquenard, H. Lecacheux, J. Livage, and C. Julien: Ortho-rhombic WO3 formed via a T-stabilized WO3 H2O phase J. Solid State Chem. 135, 159 (1998).
H-T. Sun, C. Cantalini, L. Lozzi, M. Passacantando, S. Santucci, and M. Pelino: Microstructural effect on NO2 sensitivity of WO3 thin film gas sensors Part 1. Thin film devices, sensors and actuators. Thin Solid Films 287, 258 (1996).
Y.S. Kim: Thermal treatment effects on the material and gas-sensing properties of room-temperature tungsten oxide nanorod sensors Sens. Actuators. B 137, 297 (2009).
C.D. Wagner, W.M. Riggs, L.E. Davis, and J.E. Moueler: Handbook of X-ray Photoelectron Spectroscopy, edited by G.E Muilenberg (Perkin-Elmer, Eden Prairie, MN, 1979).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Manciu, F.S., Enriquez, J.L., Durrer, W.G. et al. Spectroscopic analysis of tungsten oxide thin films. Journal of Materials Research 25, 2401–2406 (2010). https://doi.org/10.1557/jmr.2010.0294
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/jmr.2010.0294