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Improved current collection in WO3:Mo/WO3 bilayer photoelectrodes

Published online by Cambridge University Press:  31 January 2011

Eric L. Miller*
Affiliation:
Hawaii Natural Energy Institute, University of Hawaii at Manoa, Honolulu, Hawaii 96822
Bjorn Marsen
Affiliation:
Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, D-14109 Berlin, Germany
Lothar Weinhardt
Affiliation:
Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003; and Experimentelle Physik II, Universität Würzburg, D-97074 Würzburg, Germany
Marcus Bär
Affiliation:
Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, D-14109 Berlin, Germany; and Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003
Clemens Heske
Affiliation:
Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003
Mowafak M. Al-Jassim
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado 80401
*
b)This author was an editor of this focus issue during the review and decision stage. For the JMR policy on review and publication of manuscripts authored by editors, please refer to http://www.mrs.org/jmr_policy
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Abstract

We report on the incorporation of molybdenum into tungsten oxide by co-sputtering and its effect on solar-powered photoelectrochemical (PEC) water splitting. Our study shows that Mo incorporation in the bulk of the film (WO3:Mo) results in poor PEC performance when compared with pure WO3, most likely due to defects that trap photo-generated charge carriers. However, when a WO3:Mo/WO3 bilayer electrode is used, a 20% increase of the photocurrent density at 1.6 V versus saturated calomel reference electrode is observed compared with pure WO3. Morphological and microstructural analysis of the WO3:Mo/WO3 bilayer structure reveals that it is formed by coherent growth of the WO3:Mo top layer on the WO3 bottom layer. This effect allows an optimization of the electronic surface structure of the electrode while maintaining good crystallographic properties in the bulk.

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Articles
Copyright
Copyright © Materials Research Society 2010

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References

REFERENCES

1.Granqvist, C.G.Electrochromic tungsten oxide films: Review of progress 1993-1998. Sol. Energy Mater. Sol. Cells 60, 201 (2000)CrossRefGoogle Scholar
2.Solarska, R., Alexander, B.D., Augustynski, J.Electrochromic and photoelectrochemical characteristics of nanostructured WO3 films prepared by a sol-gel method. C.R. Chim. 9, 301 (2006)CrossRefGoogle Scholar
3.Washizu, E., Yamamoto, A., Abe, Y., Kawamura, M., Sasaki, K.Optical and electrochromic properties of RF reactively sputtered WO3 films. Solid State Ionics 165, 175 (2003)CrossRefGoogle Scholar
4.Smith, D.J., Vatelino, J.F., Falconer, R.S., Wittman, E.L.Stability, sensitivity and selectivity of tungsten trioxide films for sensing applications. Sens. Actuators, B 13, 264 (1993)CrossRefGoogle Scholar
5.György, E., Socol, G., Mihailescu, I.N., Ducu, C., Ciuca, S.Structural and optical characterization of WO3 thin films for gas sensor applications. J. Appl. Phys. 97, 093527 (2005)CrossRefGoogle Scholar
6.Thiele, J.A., Pereira da Cunha, M.High temperature LGS SAW gas sensor. Sens. Actuators, B 113, 816 (2006)CrossRefGoogle Scholar
7.Marsen, B., Miller, E.L., Paluselli, D., Rocheleau, R.E.Progress in sputtered tungsten trioxide for photoelectrode applications. Int. J. Hydrogen Energy 32, 3110 (2007)CrossRefGoogle Scholar
8.Santato, C., Ulmann, M., Augustynski, J.Photoelectrochemical properties of nanostructured tungsten trioxide films. J. Phys. Chem. B 105, 936 (2001)CrossRefGoogle Scholar
9.Hodes, G., Cahen, D., Manassen, J.Tungsten trioxide as a photoanode for a photoelectrochemical cell (PEC). Nature 260, 312 (1976)CrossRefGoogle Scholar
10.Desilvestro, J., Grätzel, M.J.Photoelectrochemistry of polycrystalline n-WO3: Electrochemical characterization and photoassisted oxidation processes. Electroanal. Chem. 238, 129 (1987)CrossRefGoogle Scholar
11.Gai, Y., Li, J., Li, S-S., Xia, J-B., Wei, S-H.Design of narrow-gap TiO2: A passivated codoping approach for enhanced photoelectrochemical activity. Phys. Rev. Lett. 102, 036402 (2009)CrossRefGoogle ScholarPubMed
12.Kleperis, J., Zubkans, J., Lusis, A.R.Nature of fundamental absorption edge of WO3. Proc. SPIE 2968, 186 (1997)CrossRefGoogle Scholar
13.Huda, M.N., Yan, Y., Moon, C-Y., Wei, S-H., Al-Jassim, M.M.Density-functional theory study of the effects of atomic impurity on the band edges of monoclinic WO3. Phys. Rev. B 77, 195102 (2008)CrossRefGoogle Scholar
14.Khaselev, O.K., Turner, J.A.A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splitting. Science 280, 425 (1998)CrossRefGoogle ScholarPubMed
15.Cole, B., Marsen, B., Miller, E.L., Yan, Y., To, B., Jones, K., Al-Jassim, M.M.Evaluation of nitrogen doping of tungsten oxide for photoelectrochemical water splitting. J. Phys. Chem. C 112, 5213 (2008)CrossRefGoogle Scholar
16.Baeck, S-H., Jaramillo, T.F., Jeong, D.H., McFarland, E.W.Parallel synthesis and characterization of photoelectrochemically and electrochromically active tungsten–molybdenum oxides. Chem. Commun. (Camb.) 390 (2004)CrossRefGoogle ScholarPubMed
17.Scofield, J.H.Hartree-Slater subshell photoionization cross-sections at 1254 and 1487 eV. J. Electron Spectrosc. Relat. Phenom. 8, 129 (1976)CrossRefGoogle Scholar
18.Gesheva, K., Cziraki, A., Ivanova, T., Szekeres, A.Structure and composition of thermally annealed Mo- and W-based CVD metal oxide thin films. Thin Solid Films 492, 322 (2005)CrossRefGoogle Scholar
19.Allpress, J.G., Tilley, R.J.D., Sienko, M.J.J.Examination of substoichiometric WO3-x crystals by electron microscopy. Solid State Chem. 3, 440 (1971)CrossRefGoogle Scholar
20.Weinhardt, L., Blum, M., Bär, M., Heske, C., Cole, B., Marsen, B., Miller, E.L.Electronic surface level positions of WO3 thin films for photoelectrochemical hydrogen production. J. Phys. Chem. C 112, 3078 (2008)CrossRefGoogle Scholar
21.Bär, M. et al. to be publishedGoogle Scholar