Growth and characterization of thin manganese oxide corrosion barrier layers for silicon photoanode protection during water oxidation

• Published in: Solar energy materials and solar cells Vol. 136; pp. 64 - 69
• Main Authors: O’Connor, Robert, Bogan, Justin, Fleck, Nicole, McCoy, Anthony, Walsh, Lee A., Byrne, Conor, Casey, Patrick, Hughes, Greg
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2015
• Subjects: Corrosion; Corrosion prevention; Manganese oxide; Manganese oxides; Oxidation; Photoelectrochemical cell; Protective; Resistivity; Silicon; Silicon substrates; Water oxidation; Water splitting; Photoelectrochemical cell; Water splitting; Water oxidation; Manganese oxide
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.12.028

In this work the potential of thin manganese oxide layers deposited by physical vapor deposition at moderate vacuum pressure to significantly retard the corrosion of silicon photo-anodes during the oxidation of water is reported. Results show that manganese oxide layers up to 10nm thick display sufficient transmission of solar frequency radiation and electrical conductivity to facilitate efficient oxidation of water by the underlying silicon while offering complete protection from oxidation of the silicon substrate for more than 14h. Data from x-ray photoelectron spectroscopy confirms that the increased lifetime observed when using manganese oxide as a protective layer is a result of the inhibition of the growth of silicon oxide during the reaction. [Display omitted] •Manganese oxide was deposited on silicon via physical vapour deposition.•It is found to both inhibit oxidation of the silicon and catalyse water oxidation.•XPS data confirms that manganese oxide suppresses growth of silicon oxide during water oxidation.