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Title: Band gap tuning of amorphous Al oxides by Zr alloying

Abstract

The optical band gap and electronic structure of amorphous Al-Zr mixed oxides with Zr content ranging from 4.8 to 21.9% were determined using vacuum ultraviolet and X-ray absorption spectroscopy. The light scattering by the nano-porous structure of alumina at low wavelengths was estimated based on the Mie scattering theory. The dependence of the optical band gap of the Al-Zr mixed oxides on the Zr content deviates from linearity and decreases from 7.3 eV for pure anodized Al{sub 2}O{sub 3} to 6.45 eV for Al-Zr mixed oxides with a Zr content of 21.9%. With increasing Zr content, the conduction band minimum changes non-linearly as well. Fitting of the energy band gap values resulted in a bowing parameter of ∼2 eV. The band gap bowing of the mixed oxides is assigned to the presence of the Zr d-electron states localized below the conduction band minimum of anodized Al{sub 2}O{sub 3}.

Authors:
;  [1]; ;  [2]; ;  [3]; ; ;  [4]; ; ;  [5]
  1. Department of Photonics Engineering, Technical University of Denmark, 4000 Roskilde (Denmark)
  2. ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus (Denmark)
  3. Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)
  4. Danish Technological Institute, Kongsvang Alle 29, 8000 Aarhus (Denmark)
  5. Department of Mechanical Engineering, Technical University of Denmark, 2800 Kgs-Lyngby (Denmark)
Publication Date:
OSTI Identifier:
22590494
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ABSORPTION SPECTROSCOPY; ALUMINIUM OXIDES; BOWING; ELECTRONIC STRUCTURE; LIGHT SCATTERING; NONLINEAR PROBLEMS; POROUS MATERIALS; ULTRAVIOLET RADIATION; WAVELENGTHS; X-RAY SPECTROSCOPY

Citation Formats

Canulescu, S., E-mail: stec@fotonik.dtu.dk, Schou, J., Jones, N. C., Hoffmann, S. V., Borca, C. N., Piamonteze, C., Rechendorff, K., Nielsen, L. P., Almtoft, K. P., Gudla, V. C., Bordo, K., and Ambat, R.. Band gap tuning of amorphous Al oxides by Zr alloying. United States: N. p., 2016. Web. doi:10.1063/1.4961941.
Canulescu, S., E-mail: stec@fotonik.dtu.dk, Schou, J., Jones, N. C., Hoffmann, S. V., Borca, C. N., Piamonteze, C., Rechendorff, K., Nielsen, L. P., Almtoft, K. P., Gudla, V. C., Bordo, K., & Ambat, R.. Band gap tuning of amorphous Al oxides by Zr alloying. United States. doi:10.1063/1.4961941.
Canulescu, S., E-mail: stec@fotonik.dtu.dk, Schou, J., Jones, N. C., Hoffmann, S. V., Borca, C. N., Piamonteze, C., Rechendorff, K., Nielsen, L. P., Almtoft, K. P., Gudla, V. C., Bordo, K., and Ambat, R.. 2016. "Band gap tuning of amorphous Al oxides by Zr alloying". United States. doi:10.1063/1.4961941.
@article{osti_22590494,
title = {Band gap tuning of amorphous Al oxides by Zr alloying},
author = {Canulescu, S., E-mail: stec@fotonik.dtu.dk and Schou, J. and Jones, N. C. and Hoffmann, S. V. and Borca, C. N. and Piamonteze, C. and Rechendorff, K. and Nielsen, L. P. and Almtoft, K. P. and Gudla, V. C. and Bordo, K. and Ambat, R.},
abstractNote = {The optical band gap and electronic structure of amorphous Al-Zr mixed oxides with Zr content ranging from 4.8 to 21.9% were determined using vacuum ultraviolet and X-ray absorption spectroscopy. The light scattering by the nano-porous structure of alumina at low wavelengths was estimated based on the Mie scattering theory. The dependence of the optical band gap of the Al-Zr mixed oxides on the Zr content deviates from linearity and decreases from 7.3 eV for pure anodized Al{sub 2}O{sub 3} to 6.45 eV for Al-Zr mixed oxides with a Zr content of 21.9%. With increasing Zr content, the conduction band minimum changes non-linearly as well. Fitting of the energy band gap values resulted in a bowing parameter of ∼2 eV. The band gap bowing of the mixed oxides is assigned to the presence of the Zr d-electron states localized below the conduction band minimum of anodized Al{sub 2}O{sub 3}.},
doi = {10.1063/1.4961941},
journal = {Applied Physics Letters},
number = 9,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
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