Influence of the Content of Nitrogen on the Porous-Alumina-Assisted-Anodizing of Titanium Thin Films

Influence of the Content of Nitrogen on the Porous-Alumina-Assisted-Anodizing of Titanium Thin Films

Abstract

Nanostructured titanium oxide films are widely used for numerous applications, including solar energy conversion in the form of photoelectrochemical water splitting, where an increment in the surface-to-volume ratio as well as the band-gap tuning may substantially improve the film performance. In our work to date, we have investigated the effect of the content of nitrogen on the stability of titania nanocolumn arrays formed by the porous-anodic-alumina (PAA) assisted anodizing of Al/TiNx bilayers. In addition, in order to evaluate the stabilizing mechanism, barrier-type anodizing of nitrogen-containing Ti films was performed, revealing suppression of the field-crystallization of titanium oxide. The Al/TiNx precursor layers on SiO2/Si wafers are oxidized by the PAA-assisted anodizing in organicacid-based electrolyte: the Al layer is anodized at 40 V, this being followed by reanodizing the TiNx layer to potentials up to 250 V, leading to the growth of titania nanocolumns in the alumina pores. The alumina overlayer is then partly or completely removed in a CrO3/H3PO4- based solution, in order to judge on the chemical stability of the formed nanocolumns.

Nanostructured titanium oxide films are widely used for numerous applications, including solar energy conversion in the form of photoelectrochemical water splitting, where an increment in the surface-to-volume ratio as well as the band-gap tuning may substantially improve the film performance. In our work to date, we have investigated the effect of the content of nitrogen on the stability of titania nanocolumn arrays formed by the porous-anodic-alumina (PAA) assisted anodizing of Al/TiNx bilayers. In addition, in order to evaluate the stabilizing mechanism, barrier-type anodizing of nitrogen-containing Ti films was performed, revealing suppression of the field-crystallization of titanium oxide. The Al/TiNx precursor layers on SiO2/Si wafers are oxidized by the PAA-assisted anodizing in organicacid-based electrolyte: the Al layer is anodized at 40 V, this being followed by reanodizing the TiNx layer to potentials up to 250 V, leading to the growth of titania nanocolumns in the alumina pores. The alumina overlayer is then partly or completely removed in a CrO3/H3PO4- based solution, in order to judge on the chemical stability of the formed nanocolumns.

titanium thin film; anodizing; doping

titanium thin film; anodizing; doping

BENDOVÁ, M.; KOLÁŘ, J.; HUBÁLEK, J.; MOZALEV, A.

2017

16.08.2016

Book of Abstracts of the 11th International Symposium on Electrochemical Micro and Nanosystem Technologies (EMNT2016), 17-19 Aug. 2016, Brussels, Belgium

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