|
|
Articles
by
P. Deepak Raj |
Total Records (
2 ) for
P. Deepak Raj |
|
 |
|
|
|
K.J. Kumaresh
,
P. Deepak Raj
and
M. Sridharan
|
|
The fabrication of thin film based capacitors with different metal electrodes
(Al, Cu) and their application towards void fraction measurement is carried
out in this study. Void fraction is a measure of empty spaces in any medium.
The void fraction is measured as capacitance in the capillary tube and processed
through embedded system. The thin film capacitor is designed on a capillary
tube through thermal evaporation technique with the above given metal elements.
Capillary tube with different diameters ranging from 5-10 mm and length of 7
inch were used and deposited with metal elements mentioned above with a small
distance between them. The capillary tube is used as insulator with metal elements
deposited above them as metal electrodes. Changes in capacitance value due to
the voids were measured through LCR/Z meter. Before coating the electrodes on
the capillary tubes, the films were characterized for their structural, morphological
and electrical properties to obtain capacitors with desired value of capacitance. |
|
|
|
|
M. Krishna Kumar
,
P. Deepak Raj
,
Albert Serra Torrent
,
K. Jeyadheepan
and
M. Sridharan
|
|
Zinc oxide (ZnO) films were deposited onto glass substrates using reactive direct current magnetron sputtering technique by varying the substrate bias voltage (floating potential and -50 V) and retaining other parameters, viz., deposition time, substrate temperature, argon and oxygen flow, etc., as constant. The deposited ZnO films were doped with aluminium (Al) using thermal evaporation technique and subsequently annealed at 150°C for 2 h in ambient air. Pure and Al doped films were then investigated by X-ray diffraction (XRD), UV-Visible spectroscopy, Field-Emission Scanning Electron Microscopy (FE-SEM) and four probe method for their structural, optical, morphological and electrical properties, respectively. The films were polycrystalline in nature with hexagonal wurtzite structure. Increase in the grain size value was observed for the films deposited at -50 V substrate bias voltage as well as for the films doped with Al which in turn reduced the band gap value of the films. The band gap values of the films varied between 3.34 and 3.00 eV with respect to substrate bias voltage and Al doping. The variations in the properties of the films were correlated to the change in the micro-structural parameters due to the change in the ion energy variation influenced by the variation of substrate bias voltages. |
|
|
|
|
|
|