TY - JOUR
T1 - Effect of substrate heating and microwave attenuation on the catalyst free growth and field emission of carbon nanotubes
AU - Kar, R.
AU - Sarkar, S. G.
AU - Basak, C. B.
AU - Patsha, Avinash
AU - Dhara, Sandip
AU - Ghosh, Chanchal
AU - Ramachandran, Divakar
AU - Chand, N.
AU - Chopade, S. S.
AU - Patil, D. S.
N1 - Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/8/29
Y1 - 2015/8/29
N2 - Carbon nanotubes (CNTs) have been directly grown on Inconel 600 substrates by microwave plasma enhanced chemical vapor deposition without using any external catalyst. Grown CNTs were characterized by field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and field emission measurements. Characterization results show that field emission current density increases from 200 μA/cm2 at ∼5.5 V/μm to 14.5 mA/cm2 at ∼1.6 V/μA when substrate is heat-treated and incident microwave is attenuated before reaching it. Detailed characterization reveals that heat-treatment results in migration of Cr and Fe oxides towards the top surface which completely changes substrate morphology also. Microwave attenuation reduces reflection of microwaves from the substrate and increases residence time of the precursor over the substrate promoting high density growth of CNTs. The combination of these two process parameters resulted in growth of long, dense CNTs with bamboo-like defects that contributes to enhanced current density at lower applied field.
AB - Carbon nanotubes (CNTs) have been directly grown on Inconel 600 substrates by microwave plasma enhanced chemical vapor deposition without using any external catalyst. Grown CNTs were characterized by field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and field emission measurements. Characterization results show that field emission current density increases from 200 μA/cm2 at ∼5.5 V/μm to 14.5 mA/cm2 at ∼1.6 V/μA when substrate is heat-treated and incident microwave is attenuated before reaching it. Detailed characterization reveals that heat-treatment results in migration of Cr and Fe oxides towards the top surface which completely changes substrate morphology also. Microwave attenuation reduces reflection of microwaves from the substrate and increases residence time of the precursor over the substrate promoting high density growth of CNTs. The combination of these two process parameters resulted in growth of long, dense CNTs with bamboo-like defects that contributes to enhanced current density at lower applied field.
UR - http://www.scopus.com/inward/record.url?scp=84940366332&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2015.07.002
DO - 10.1016/j.carbon.2015.07.002
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AN - SCOPUS:84940366332
SN - 0008-6223
VL - 94
SP - 256
EP - 265
JO - Carbon
JF - Carbon
ER -