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Spatial decoupling of light absorption and catalytic activity of Ni–Mo-loaded high-aspect-ratio silicon microwire photocathodes

Nature Energyvolume 3pages185192 (2018) | Download Citation


A solar-driven photoelectrochemical cell provides a promising approach to enable the large-scale conversion and storage of solar energy, but requires the use of Earth-abundant materials. Earth-abundant catalysts for the hydrogen evolution reaction, for example nickel–molybdenum (Ni–Mo), are generally opaque and require high mass loading to obtain high catalytic activity, which in turn leads to parasitic light absorption for the underlying photoabsorber (for example silicon), thus limiting production of hydrogen. Here, we show the fabrication of a highly efficient photocathode by spatially and functionally decoupling light absorption and catalytic activity. Varying the fraction of catalyst coverage over the microwires, and the pitch between the microwires, makes it possible to deconvolute the contributions of catalytic activity and light absorption to the overall device performance. This approach provided a silicon microwire photocathode that exhibited a near-ideal short-circuit photocurrent density of 35.5 mA cm−2, a photovoltage of 495 mV and a fill factor of 62% under AM 1.5G illumination, resulting in an ideal regenerative cell efficiency of 10.8%.

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The Netherlands Organization for Scientific Research (NWO) is acknowledged for financial support (FOM projects 13CO12-1 and 13CO12-2, and MESA+ School for Nanotechnology grant 022.003.001). A. Milbrat and G. Mul are acknowledged for assistance with the gas chromatography measurements.

Author information


  1. Molecular NanoFabrication, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands

    • Wouter Vijselaar
    • , Janneke Veerbeek
    •  & Jurriaan Huskens
  2. Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands

    • Pieter Westerik
    • , Roald M. Tiggelaar
    • , Erwin Berenschot
    • , Niels R. Tas
    •  & Han Gardeniers
  3. NanoLab Cleanroom, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands

    • Roald M. Tiggelaar


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W.V., P.W., J.V. and E.B. performed the experimental work, W.V., P.W., N.R.T. and R.M.T. planned the project and performed the data analysis, W.V., H.G. and J.H. conceived the idea, and all authors contributed to the writing of the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Han Gardeniers or Jurriaan Huskens.

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  1. Supplementary Information

    Supplementary Figures 1–17, Supplementary Tables 1–5, Supplementary Discussion and Supplementary References

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