An Electrochemical, Microtopographical and Ambient Pressure X-Ray Photoelectron Spectroscopic Investigation of Si/TiO2/Ni/Electrolyte Interfaces
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Chemistry and Chemical Engineering. Joint Center for Artificial Photosynthesis
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source. Materials Science Division. Joint Center for Artificial Photosynthesis
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division. Joint Center for Artificial Photosynthesis
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis. Beckman Inst.
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Chemistry and Chemical Engineering. Joint Center for Artificial Photosynthesis. Beckman Inst. Kavli Nanoscience Inst.
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source; Chinese Academy of Sciences (CAS), Shanghai (China). State Key Lab. of Functional Materials for Informatics. Shanghai Inst. of Microsystem and Information Technology; ShanghaiTech Univ. (China). School of Physical Science and Technology
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis
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 control to 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.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- Contributing Organization:
- Chinese Academy of Sciences (CAS), Shanghai (China); ShanghaiTech Univ. (China)
- Grant/Contract Number:
- AC02-05CH11231; SC0004993
- OSTI ID:
- 1378770
- Journal Information:
- Journal of the Electrochemical Society, Vol. 163, Issue 2; ISSN 0013-4651
- Publisher:
- The Electrochemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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