Study on Structural, Thermal, Optical, Electrical and Nanomechanical Properties of Sputtered Vanadium Oxide Smart Thin Films

Porwal, D and Esther, CM and Reddy, IN and Sridhara, N and Yadav, NP and Rangappa, D and Bera, Parthasarathi and Anandan, C and Sharma, AK and Dey, Arjun (2015) Study on Structural, Thermal, Optical, Electrical and Nanomechanical Properties of Sputtered Vanadium Oxide Smart Thin Films. RSC Advances, 45 (5). pp. 35737-35745.

[img] PDF
Restricted to Registered users only

Download (980kB) | Request a copy
Official URL: 10.1039/C5RA02092A


Vanadium oxide thin films were grown on both quartz and Si(111) substrates, utilizing a pulsed RF magnetron sputtering technique at room temperature with the RF powers at 100 W to 700 W. The corresponding thicknesses of the films were increased from 27.5 nm to 243 nm and 21 nm to 211 nm as the RF power was increased from 100 W to 700 W for the quartz and silicon substrates, respectively. X-ray diffraction and field emission scanning electron microscopy were carried out to investigate the phase and surface morphology of the deposited films. The electronic structure and the vanadium oxidation states of the deposited films were investigated thoroughly by X-ray photoelectron spectroscopy. The as-grown films show only stoichiometric vanadium oxide, where vanadium is in V5+ and V4+ states. The phase transitions of the vanadium oxide films were investigated by the differential scanning calorimetric technique. The reversible i.e. smart transition was observed in the region from 337 °C to 343 °C. The average hemispherical infrared emittance of the deposited vanadium oxide films was evaluated by an emissometer in the wavelength range of 3 μm to 30 μm. The sheet resistance of the deposited films was measured by a two-probe method and the data were in the range of 106 to 105 Ω per square. The optical properties of the films, such as solar transmittance, solar reflectance and solar absorptance, as well as optical constants e.g. optical band gap, were also evaluated. Finally, mechanical properties such as the hardness and the Young’s modulus at the microstructural length scale were evaluated by employing a nanoindentation technique with a continuous stiffness mode.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s. Royal Society of Chemistry
Uncontrolled Keywords: Vanadium oxide;Emissometer;Nanoindentation technique;Nanohardness
Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
Depositing User: Ms. Alphones Mary
Date Deposited: 02 May 2016 04:10
Last Modified: 02 May 2016 04:10

Actions (login required)

View Item View Item