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Improved current collection in WO3:Mo/WO3 bilayer photoelectrodes

  • Nicolas Gaillard, Brian Cole, Jess Kaneshiro, Eric L. Miller (a1), Bjorn Marsen (a2), Lothar Weinhardt (a3), Marcus Bär (a4), Clemens Heske (a5), Kwang-Soon Ahn, Yanfa Yan and Mowafak M. Al-Jassim (a6)...

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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Corresponding author

a)Address all correspondence to this author. e-mail: ngaillar@hawaii.edu
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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21.Bär, M. et al. to be published

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