skip to main content

DOE PAGESDOE PAGES

Title: An Electrochemical, Microtopographical and Ambient Pressure X-Ray Photoelectron Spectroscopic Investigation of Si/TiO 2/Ni/Electrolyte Interfaces

The electrical and spectroscopic properties of the TiO 2/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-TiO 2/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 TiO 2 surface. At low loadings of Ni, the Ni was present primarily as an oxide layer and the samples were not conductive, although the TiO 2 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 TiO 2/Ni electrodes and to contextualize the AP-XPS results.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [2] ;  [5] ;  [6] ;  [7] ;  [8]
  1. California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Chemistry and Chemical Engineering. Joint Center for Artificial Photosynthesis
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source. Materials Science Division. Joint Center for Artificial Photosynthesis
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division. Joint Center for Artificial Photosynthesis
  5. California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis. Beckman Inst.
  6. 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.
  7. 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
  8. California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis
Publication Date:
Grant/Contract Number:
AC02-05CH11231; SC0004993
Type:
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 163; Journal Issue: 2; Journal ID: ISSN 0013-4651
Publisher:
The Electrochemical Society
Research Org:
California Inst. of Technology (CalTech), Pasadena, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Contributing Orgs:
Chinese Academy of Sciences (CAS), Shanghai (China); ShanghaiTech Univ. (China)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; corrosion; interfaces; photoelectrochemistry; semiconductor/liquid junction
OSTI Identifier:
1378770