Back-Illuminated Si-Based Photoanode with Nickel Cobalt Oxide Catalytic Protection Layer

Dowon Bae, Bastian Mei, Rasmus Frydendal, Thomas Pedersen, Brian Seger, Ole Hansen, Peter C. K. Vesborg, Ib Chorkendorff*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Si is an excellent photo-absorber for use in dual-band-gap photoelectrochemical water splitting. We investigate photoanodes with n+pp+-Si configuration under back-side illumination, which is suited to work in a tandem device stack. A co-sputtered NiCoOx film coupled to the Si was used as a protective catalyst for the water oxidation reaction in 1 m KOH. The sample showed a high photocurrent (21 mA cm−2) under red-light illumination (38.6 mW cm−2). Long-term stability testing showed a gradual decrease of activity in the beginning, and then the activity increased, yielding a cathodic shift of the onset voltage (>50 mV), likely owing to the divergent response of Ni and Co to the Fe present in KOH. Once the activity of the sample stabilized, no further degradation was observed for the following 6 days, indicating that the demonstrated back-illuminated photoanode configuration can be considered a promising architecture for use as a bottom cell of the tandem water-splitting device under alkaline conditions.

Original languageEnglish
Pages (from-to)1546-1552
Number of pages7
Issue number10
Early online date25 Jan 2016
Publication statusPublished - Oct 2016


  • nickel cobalt oxide
  • oxygen evolution
  • photocatalysis
  • solar fuel
  • water splitting

ASJC Scopus subject areas

  • Catalysis
  • Electrochemistry


Dive into the research topics of 'Back-Illuminated Si-Based Photoanode with Nickel Cobalt Oxide Catalytic Protection Layer'. Together they form a unique fingerprint.

Cite this