Low temperature charge carrier hopping transport mechanism in vanadium oxide thin films grown using pulsed dc sputtering

2009 ◽  
Vol 94 (22) ◽  
pp. 222110 ◽  
Author(s):  
S. S. N. Bharadwaja ◽  
C. Venkatasubramanian ◽  
N. Fieldhouse ◽  
S. Ashok ◽  
M. W. Horn ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Charge Carrier ◽  
Vanadium Oxide ◽  
Transport Mechanism ◽  
Oxide Thin Films ◽  
Hopping Transport ◽  
Dc Sputtering ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

Vanadium oxide thin films for bolometric applications deposited by reactive pulsed dc sputtering

2009 ◽  
Vol 27 (4) ◽  
pp. 951-955 ◽  
Author(s):  
N. Fieldhouse ◽  
S. M. Pursel ◽  
R. Carey ◽  
M. W. Horn ◽  
S. S. N. Bharadwaja
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Oxide Thin Films ◽  
Dc Sputtering ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

Process-structure-property correlations in pulsed dc reactive magnetron sputtered vanadium oxide thin films

2011 ◽  
Vol 29 (6) ◽  
pp. 061504 ◽  
Author(s):  
Chandrasekaran Venkatasubramanian ◽  
Orlando M. Cabarcos ◽  
William R. Drawl ◽  
David L. Allara ◽  
S. Ashok ◽  
...  
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Reactive Magnetron ◽  
Structure Property ◽  
Oxide Thin Films ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films ◽  
Process Structure ◽  
Property Correlations

Stoichiometry and microstructural effects on electrical conduction in pulsed dc sputtered vanadium oxide thin films

2009 ◽  
Vol 24 (4) ◽  
pp. 1590-1599 ◽  
Author(s):  
Bryan D. Gauntt ◽  
Elizabeth C. Dickey ◽  
Mark W. Horn
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Temperature Coefficient ◽  
Oxygen Content ◽  
Equilibrium Phase ◽  
Electron Diffraction Data ◽  
Cubic Phase ◽  
Oxide Thin Films ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

Vanadium oxide thin films were deposited using pulsed direct current (dc) magnetron sputtering in an atmosphere containing argon and oxygen. The total pressure was varied from 2.5 to 15 mTorr, and the oxygen-to-argon ratio was varied from 2.5 to 30%. The resulting films were characterized using Rutherford backscattering spectroscopy (RBS), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and glancing incidence x-ray diffraction (GIXRD). Electrical resistivity was calculated from I–V curves acquired from two-point-probe measurements and thicknesses measured from bright-field TEM images of cross-sectioned samples. TEM and GIXRD were used to characterize the crystallinity of each film. A transition from nanocrystalline to amorphous growth was observed with increasing partial pressure of oxygen. In all samples, the only crystalline phase observed was cubic vanadium oxide with the sodium chloride structure. Though the cubic VOx equilibrium phase field is limited to a maximum of x = 1.3, the cubic phase was observed with a value of x up to 2 in the present work. It was apparent from electron diffraction data that increased oxygen content correlated with an increase in the film disorder. The increase in oxygen content also corresponded with an increase in the film resistivity, which varied over 7 orders of magnitude from 1.18 × 10−3 to 2.98 × 104 Ω·cm. The temperature coefficient of resistance was found to increase with increasing oxygen content from −0.1 to −3.5%/°C. A direct correlation between film disorder and temperature coefficient of resistivity (TCR) was observed and could be exploited to engineer materials with the desired TCR.

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