Rawal, Ishpal and Panwar, Omvir Singh and Tripathi, Ravi Kant and Srivastava, Avanish Kumar and Kumar, Mahesh and Chockalingam, Sreekumar (2015) Structural and nanomechanical properties of nanocrystalline carbon thin films for photodetection. Journal of Vacuum Science and Technology A, 33 (3). ISSN 0734-2101

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Abstract

This paper reports the effect of helium gas pressure upon the structural, nanomechanical, and photoconductive properties of nanocrystalline carbon thin (NCT) films deposited by the filtered cathodic jet carbon arc technique. High-resolution transmission electron microscopy images confirm the nanocrystalline nature of the deposited films with different crystallite sizes (3-7 nm). The chemical structure of the deposited films is further analyzed by x-ray photoelectron spectroscopy and Raman spectroscopy, which suggest that the deposited films change from graphitelike to diamondlike, increasing in sp(3) content, with a minor change in the dilution of the inert gas (helium). The graphitic character is regained upon higher dilution of the helium gas, whereupon the films exhibit an increase in sp(2) content. The nanomechanical measurements show that the film deposited at a helium partial pressure of 2.2 x 10(-4) has the highest value of hardness (37.39 GPa) and elastic modulus (320.50 GPa). At a light intensity of 100 mW/cm(2), the NCT films deposited at 2.2 x 10(-4) and 0.1 mbar partial pressures of helium gas exhibit good photoresponses of 2.2% and 3.6%, respectively.

Item Type:	Article
Subjects:	Materials Science Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	13 Oct 2016 07:43
Last Modified:	13 Oct 2016 07:43
URI:	http://npl.csircentral.net/id/eprint/1996

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