Author, as appears in the article.: Mozalev A; Vázquez R; Bittencourt C; Cossement D; Gispert-Guirado F; Llobet E; Habazaki H
Department: Enginyeria Electrònica, Elèctrica i Automàtica
URV's Author/s: Gispert Guirado, Francesc / GUIRADO PAGÉS, FRANCISCO / Llobet Valero, Eduard / VÁZQUEZ FERNÁNDEZ, ROSA MARÍA
Abstract: Nanostructured niobium oxide (NO) semiconductors are gaining increasing attention as electronic, optical, and electro-optic materials. However, the preparation of stable NO nanofilms with reproducible morphology and behavior remains a challenge. Here we show a rapid, well-controlled, and efficient way to synthesize NO films with self-organized columnlike nanostructured morphologies and advanced functional properties. The films are developed via the growth of a nanoporous anodic alumina layer, followed by the pore-directed anodization of the Nb underlayer. The columns may grow 30-150 nm wide, up to 900 nm long, with an aspect ratio of up to 20, being anchored to a thin continuous oxide layer that separates the columns from the substrate. The as-anodized films have a graded chemical composition changing from amorphous Nb2O5 mixed with Al2O3, Si-, and P-containing species in the surface region to NbO2 in the lower film layer. The post-anodization treatments result in the controlled formation of Nb2O5, NbO2, and NbO crystal phases, accompanied by transformation from nearly perfect dielectric to n-type semiconductor behavior of the films. The approach allows for the smooth film growth without early dielectric breakdown, stress-generated defects, or destructive dissolution at the respective interfaces, which is a unique situation in the oxide films on niobium. The functional properties of the NO films, revealed to date, allow for potential applications as nanocomposite capacitor dielectrics and active layers for semiconductor gas microsensors with the sensitivity to ethanol and the response to hydrogen being among best ever reported. This journal is © the Partner Organisations 2014.
Thematic Areas: Química Physics, applied Odontología Materials science, multidisciplinary Materials chemistry Materiais Interdisciplinar General chemistry Engenharias iii Ciências ambientais Ciências agrárias i Chemistry (miscellaneous) Chemistry (all) Biotecnología Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 20507526
Author's mail: eduard.llobet@urv.cat
Author identifier: 0000-0001-6164-4342
Record's date: 2024-07-27
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://www.rsc.org/suppdata/tc/c4/c4tc00349g/c4tc00349g1.pdf
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Journal Of Materials Chemistry c. 2 (24): 4847-4860
APA: Mozalev A; Vázquez R; Bittencourt C; Cossement D; Gispert-Guirado F; Llobet E; Habazaki H (2014). Formation-structure-properties of niobium-oxide nanocolumn arrays via self-organized anodization of sputter-deposited aluminum-on-niobium layers. Journal Of Materials Chemistry c, 2(24), 4847-4860. DOI: 10.1039/c4tc00349g
Article's DOI: 10.1039/c4tc00349g
Entity: Universitat Rovira i Virgili
Journal publication year: 2014
Publication Type: Journal Publications