Abstract
We report controlled modifications in the semiconductor-to-metal transition characteristics of VO2 single-crystal thin films induced by swift heavy ion (SHI) irradiation with varying ion fluences. At very high energies of ions (200 MeV Au), the electronic stopping (~2009 eV/Å) dominates over nuclear stopping (~16 eV/Å). Under these extreme electronic excitation conditions caused by electronic stopping and the passage of SHIs through the entire thickness of the film, creation of certain unique type of defects and disordered regions occurs. X-ray diffraction, Raman spectroscopy, infrared transmission spectroscopy, x-ray photoelectron spectroscopy (XPS), and electrical measurements were performed to investigate the characteristics and role of these defects on structural, optical, and electrical properties of VO2 thin films. XPS and electrical resistivity measurements suggest that the ion irradiation induces localized defect states that appear to correlate well with the creation of disordered regions in the VO2 thin films. The high-energy heavy-ion irradiation changes the transition characteristics drastically from a first-order to a second-order transition (electronic—Mott type). The low-temperature conductance data for these ion-irradiated films fit well with the quasiamorphous model for resistivity of VO2, where ion irradiation is believed to create mid-bandgap defect states.
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References
F.J. Morin: Oxides which show a metal-to-insulator transition at the Neel temperature. Phys. Rev. Lett. 3, 34 (1959).
J. Nag and R.F. Haglund Jr.: Synthesis of vanadium dioxide thin films and nanoparticles. J. Phys. Condens. Matter. 20, 264016 (2008).
J. Narayan and V. Bhosle: Phase transition and critical issues in structure-property correlations of vanadium oxide. J. Appl. Phys. 100, 103524 (2006).
C.H. Griffiths and H.K. Eastwood: Influence of stoichiometry on metal–semiconductor transition in vanadium dioxide. J. Appl. Phys. 45, 2201 (1974).
T-H. Yang, R. Aggarwal, A. Gupta, H. Zhou, R.J. Narayan, and J. Narayan: Semiconductor-metal transition characteristics of VO2 thin films grown on c- and r-sapphire substrates. J. Appl. Phys. 107, 053514 (2010).
A. Gupta, R. Aggarwal, P. Gupta, T. Dutta, R.J. Narayan, and J. Narayan: Semiconductor to metal transition characteristics of VO2 thin films grown epitaxially on Si (001). Appl. Phys. Lett. 95, 11915 (2009).
F.C. Case: Modifications in the phase transition properties of predeposited VO2 films. J. Vac. Sci. Technol. A 2 (4), 1509 (1984).
F.C. Case: Effects of low-energy low-flux ion bombardment on the properties of VO2 thin films. J. Vac. Sci. Technol. A 7 (3), 1194 (1989).
A. Leone, A.M. Trione, and F. Junga: Alteration in electrical and infrared switching properties of vanadium oxides due to proton irradiation. IEEE Trans. Nucl. Sci. 37 (6), 1739 (1990).
L-B. Lin, T-C. Lu, Q. Liu, Y. Lu, and X-D. Feng: Phase-transition properties of VO2 thin films changed by high flux electron beam radiation. Surf. Coat. Technol. 158–, 530 (2002).
M.A. Nastasi, J.W. Mayer, and J.K. Hirvonen: Ion-Solid Interactions: Fundamentals and Applications (Cambridge University Press, Cambridge, England, 1996), p. 141.
J.F. Ziegler, P. Biersack, and U. Littmark: Stopping and Ranges of Ions in Matter (Pergamon, New York, 1985).
M. Toulemonde, J.M. Constantini, C. Dufour, A. Meftah, E. Paumier, and F. Studer: Track creation in SiO. Nucl. Instrum. Methods Phys. Res. B 116, 37 (1996).
D.K. Avasthi, W. Assmann, H. Notle, H.D. Mieskes, S. Ghosh, and N.C. Mishra: Transport of oxygen atoms mediated by electronic excitation. Nucl. Instrum. Methods Phys. Res. B 166, 345 (2000).
P. Schilbe: Raman scattering in VO2. Physica B 316, 600 (2002).
K. Nishida, M. Osada, H. Takeuchi, I. Yosiaki, J. Sakai, N. Ito, R. Ikariyama, T. Kamo, T. Fujisawa, H. Funakubo, T. Katoda, and T. Yamamoto: Raman spectroscopy study of oxygen vacancies in PbTiO3 thin films generated heat-treated in hydrogen atmosphere. Jpn. J. Appl. Phys. 47, 7510 (2008).
J.C. Parker: Raman scattering from VO2 single crystals: A study of the effects of surface oxidation. Phys. Rev. B 42 (5), 3164 (1990).
A.Z. Moshfegh and A. Ignatiev: Formation and characterization of thin film vanadium oxides: Auger electron spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, scanning electron microscopy, and optical reflectance studies. Thin Solid Films 198, 251 (1991).
G.A. Sawatzky and D. Post: X-ray photoelectron and Auger spectroscopy study of some vanadium oxides. Phys. Rev. B 20, 1546 (1979).
V.A. Klimov, I.O. Timofeeva, S.D. Khanin, E.B. Shadrin, A.V. Il’inskiÏ, and F. Silva-Andrade: Effect of crystallization of amorphous vanadium dioxide films on the parameters of a semiconductor-metal phase transition. Semiconductors 37, 370 (2003).
C. Ko and S. Ramanathan: Observation of electric field-assisted phase transition in thin film vanadium oxide in a metal-oxide-semiconductor device geometry. Appl. Phys. Lett. 93, 252101 (2008).
G. Von Schulthess and P. Wachter: First observation of photoconductivity in the semiconducting phase of VO2. Solid State Commun. 15, 1645 (1974).
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Gupta, A., Singhal, R., Narayan, J. et al. Electronic excitation induced controlled modifications of semiconductor-to-metal transition in epitaxial VO2 thin films. Journal of Materials Research 26, 2901–2906 (2011). https://doi.org/10.1557/jmr.2011.392
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DOI: https://doi.org/10.1557/jmr.2011.392