Abstract
The electrical and spectroscopic properties of the TiO2/Ni protection layer system, which enables stabilization of otherwise corroding photoanodes, have been investigated in contact with electrolyte solutions by scanning-probe microscopy, electrochemistry and in-situ ambient pressure X-ray photoelectron spectroscopy (AP-XPS). Specifically, the energy-band relations of the p+-Si/ALD-TiO2/Ni interface have been determined for a selected range of Ni thicknesses. AP-XPS measurements using tender X-rays were performed in a three-electrode electrochemical arrangement under potentiostatic controlto obtain information from the semiconductor near-surface region, the electrochemical double layer (ECDL) and the electrolyte beyond the ECDL. The degree of conductivity depended on the chemical state of the Ni on the TiO2 surface. At low loadings of Ni, the Ni was present primarily as an oxide layer and the samples were not conductive, although the TiO2 XPS core levels nonetheless displayed behavior indicative of a metal-electrolyte junction. In contrast, as the Ni thickness increased, the Ni phase was primarily metallic and the electrochemical behavior became highly conductive, with the AP-XPS data indicative of a metal-electrolyte junction. Electrochemical and microtopographical methods have been employed to better define the nature of the TiO2/Ni electrodes and to contextualize the AP-XPS results.
| Original language | English |
|---|---|
| Pages (from-to) | H139-H146 |
| Journal | Journal of the Electrochemical Society |
| Volume | 163 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2016 |
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ASJC Scopus subject areas
- Electrochemistry
- Electronic, Optical and Magnetic Materials
- Materials Chemistry
- Surfaces, Coatings and Films
- Renewable Energy, Sustainability and the Environment
- Condensed Matter Physics
Cite this
An electrochemical, microtopographical and ambient pressure x-ray photoelectron spectroscopic investigation of Si/TiO2/Ni/electrolyte interfaces. / Lichterman, Michael F.; Richter, Matthias H.; Hu, Shu; Crumlin, Ethan J.; Axnanda, Stephanus; Favaro, Marco; Drisdell, Walter; Hussain, Zahid; Brunschwig, Bruce S.; Lewis, Nathan S; Liu, Zhi; Lewerenz, Hans Joachim.
In: Journal of the Electrochemical Society, Vol. 163, No. 2, 2016, p. H139-H146.Research output: Contribution to journal › Article
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TY - JOUR
T1 - An electrochemical, microtopographical and ambient pressure x-ray photoelectron spectroscopic investigation of Si/TiO2/Ni/electrolyte interfaces
AU - Lichterman, Michael F.
AU - Richter, Matthias H.
AU - Hu, Shu
AU - Crumlin, Ethan J.
AU - Axnanda, Stephanus
AU - Favaro, Marco
AU - Drisdell, Walter
AU - Hussain, Zahid
AU - Brunschwig, Bruce S.
AU - Lewis, Nathan S
AU - Liu, Zhi
AU - Lewerenz, Hans Joachim
PY - 2016
Y1 - 2016
N2 - The electrical and spectroscopic properties of the TiO2/Ni protection layer system, which enables stabilization of otherwise corroding photoanodes, have been investigated in contact with electrolyte solutions by scanning-probe microscopy, electrochemistry and in-situ ambient pressure X-ray photoelectron spectroscopy (AP-XPS). Specifically, the energy-band relations of the p+-Si/ALD-TiO2/Ni interface have been determined for a selected range of Ni thicknesses. AP-XPS measurements using tender X-rays were performed in a three-electrode electrochemical arrangement under potentiostatic controlto obtain information from the semiconductor near-surface region, the electrochemical double layer (ECDL) and the electrolyte beyond the ECDL. The degree of conductivity depended on the chemical state of the Ni on the TiO2 surface. At low loadings of Ni, the Ni was present primarily as an oxide layer and the samples were not conductive, although the TiO2 XPS core levels nonetheless displayed behavior indicative of a metal-electrolyte junction. In contrast, as the Ni thickness increased, the Ni phase was primarily metallic and the electrochemical behavior became highly conductive, with the AP-XPS data indicative of a metal-electrolyte junction. Electrochemical and microtopographical methods have been employed to better define the nature of the TiO2/Ni electrodes and to contextualize the AP-XPS results.
AB - The electrical and spectroscopic properties of the TiO2/Ni protection layer system, which enables stabilization of otherwise corroding photoanodes, have been investigated in contact with electrolyte solutions by scanning-probe microscopy, electrochemistry and in-situ ambient pressure X-ray photoelectron spectroscopy (AP-XPS). Specifically, the energy-band relations of the p+-Si/ALD-TiO2/Ni interface have been determined for a selected range of Ni thicknesses. AP-XPS measurements using tender X-rays were performed in a three-electrode electrochemical arrangement under potentiostatic controlto obtain information from the semiconductor near-surface region, the electrochemical double layer (ECDL) and the electrolyte beyond the ECDL. The degree of conductivity depended on the chemical state of the Ni on the TiO2 surface. At low loadings of Ni, the Ni was present primarily as an oxide layer and the samples were not conductive, although the TiO2 XPS core levels nonetheless displayed behavior indicative of a metal-electrolyte junction. In contrast, as the Ni thickness increased, the Ni phase was primarily metallic and the electrochemical behavior became highly conductive, with the AP-XPS data indicative of a metal-electrolyte junction. Electrochemical and microtopographical methods have been employed to better define the nature of the TiO2/Ni electrodes and to contextualize the AP-XPS results.
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U2 - 10.1149/2.0861602jes
DO - 10.1149/2.0861602jes
M3 - Article
VL - 163
SP - H139-H146
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 2
ER -