Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-29T11:54:09.406Z Has data issue: false hasContentIssue false
  • English
  • Français

Influence of Nitrogen Doping on Tungsten Oxide Thin Films for Photoelectrochemical Water Splitting

Published online by Cambridge University Press:  26 February 2011

Brian Cole ,
Bjorn Marsen  and
Eric Miller
Brian Cole
Affiliation:
bcole@hawaii.edu, University of Hawaii at Manoa, Hawaii Natural Energy Institute, 1680 East West Road, POST 109, Honolulu, HI, 96822, United States, 808-956-5229
Bjorn Marsen
Affiliation:
marsen@hawaii.edu, University of Hawaii, Hawaii Natural Energy Institute, 1680 East West Road, POST 109, Honolulu, HI, 96822, United States
Eric Miller
Affiliation:
ericm@hawaii.edu, University of Hawaii, Hawaii Natural Energy Institute, 1680 East West Road, POST 109, Honolulu, HI, 96822, United States
Get access

Abstract

Thin films of tungsten oxide were investigated for use as a top junction in a hybrid photoelectrode. To increase the solar to hydrogen efficiency, the tungsten oxide requires a bandgap reduction to the range of 2.2 to 2.4 eV. Nitrogen doping of WO3 films was employed to reduce the bandgap via valence band modification. For low levels of doping, the bandgap was observed to increase, an effect attributed to decreased size of the polycrystals in the film. The photoelectrochemical efficiency was found to decrease from 80% for pure WO3 to 56% for films deposited at a nitrogen partial pressure of 1.5 mTorr. For even higher doping levels (to 5 mTorr N2), the bandgap was shown to decrease to a value of ∼1.9 eV, but the structural data indicates that significant disorder had been introduced. This disorder is consistent with recurrent dislocations, an effect that is common for the tungsten oxide material.

Keywords

thin filmoptical propertiesphotochemical
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 974: Symposium CC – Solar Energy Conversion , 2006 , 0974-CC09-04
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1) Turner, J., Science 305, 972 (2004).10.1126/science.1103197Google Scholar
2) Desilvestro, J. and Gratzel, M., J. Electroanal. Chem. 238, 129 (1987).10.1016/0022-0728(87)85170-7Google Scholar
3) Santato, C., Ulmann, M., and Augustynski, J., J. Phys. Chem. B 105, 936 (2001).10.1021/jp002232qGoogle Scholar
4) Miller, E., Rocheleau, R. E., and Deng, X. M., Inter. J. Hydrogen Energy 28, 615 (2003).10.1016/S0360-3199(02)00144-1Google Scholar
5) Miller, E., Paluselli, D., Marsen, B., and Rocheleau, R., Electochemical and Solid State Letters 8, A247 (2005).Google Scholar
6) Miller, E., Department of Energy – Hydrogen Program Review, Arlington VA (2006).Google Scholar
7) Paluselli, D., Marsen, B., Miller, E., and Rocheleau, R., Electochemical and Solid State Letters 8, G301 (2005).10.1149/1.2042629Google Scholar
8) Asahi, R., Morikawa, T., Ohwaki, T., Aoki, K., Taga, Y., Science 293, 269 (2001).10.1126/science.1061051Google Scholar
9) Wood, D. and Tauc, J., Physical Review B 5, 3144 (1972).10.1103/PhysRevB.5.3144Google Scholar
10) Miller, E. L., Marsen, B., Cole, B., and Lum, M., Electrochem. Solid-State Lett 9, G248 (2006).Google Scholar
11) Magneli, A., Acta Cryst. 6, 495 (1953).10.1107/S0365110X53001381Google Scholar
12) Sundberg, M., J. Solid State Chem. 35, 120 (1980).Google Scholar
13) Allpress, J.G., Tilley, R., and Sienko, M., J. Solid State Chem. 3, 440 (1971).10.1016/0022-4596(71)90083-1Google Scholar
14) Green, M. and Hussain, Z., J. Appl. Phys. 69, 7788 (1991).Google Scholar