Publication detail

Formation structure properties of niobium oxide nanocolumn arrays via self organized anodization of sputter deposited aluminum on niobium layers

MOZALEV, A. VAZQUEZ, R. BITTENCOURT, C. COSSEMENT, D. GISPERT-GUIRADO, F. LLOBET, E. HABAZAKI, H.

Original Title

Formation structure properties of niobium oxide nanocolumn arrays via self organized anodization of sputter deposited aluminum on niobium layers

Type

journal article in Web of Science

Language

English

Original 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.

Keywords

niobium oxide, anodization, semiconductor, analytical investigation, dielectric properties, gas sensors

Authors

MOZALEV, A.; VAZQUEZ, R.; BITTENCOURT, C.; COSSEMENT, D.; GISPERT-GUIRADO, F.; LLOBET, E.; HABAZAKI, H.

RIV year

2014

Released

30. 4. 2014

Publisher

Royal Society of Chemistry (RSC), England

Location

Cambridge, England

ISBN

0959-9428

Periodical

JOURNAL OF MATERIALS CHEMISTRY

Year of study

2

Number

-

State

United Kingdom of Great Britain and Northern Ireland

Pages from

4847

Pages to

4860

Pages count

14

BibTex

@article{BUT110839,
  author="Alexander {Mozalev} and Rosa Maria {Vazquez} and Ca. {Bittencourt} and Damien {Cossement} and Francesc {Gispert-Guirado} and Eduard {Llobet} and Hiroki {Habazaki}",
  title="Formation structure properties of niobium oxide nanocolumn arrays via self organized anodization of sputter deposited aluminum on niobium layers",
  journal="JOURNAL OF MATERIALS CHEMISTRY",
  year="2014",
  volume="2",
  number="-",
  pages="4847--4860",
  doi="10.1039/c4tc00349g",
  issn="0959-9428"
}