Authors: H. Sharma, V. Kaushik, A.K. Shukla, V.D. Vankar
Affilation: Indian Institute of Technology Delhi, India
Pages: 300 - 303
Keywords: CNTs, field emission, micro Raman, HRTEM
we report the role of Ti on the growth and field emission properties of multiwalled carbon nanotubes (MWCNTs), prepared by microwave plasma enhanced chemical vapour deposition technique (MPECVD). First set of studies were carried out by depositing Ti as an underlayer to investigate the effect of Ti on the growth of MWCNTs. In the second set of studies, CNTs were coated with Ti as top layer of very small thicknesses (1.5 nm) and their field emission behaviour was investigated. The turn on and threshold field values of Ti modified CNTs were found to be low ~ 0.8 V/µm and 2.65 V/µm, respectively, as compared to pure CNTs. HRTEM studies proved that Ti sits on the edges by depositing as top layer and adheres on the CNT walls. This improved adhesion and bonding with CNTs is due to the unfilled d-shell of Ti, resulting in the modification of CNTs structure. Micro Raman spectroscopy confirmed the improved crystallanity of CNTs by depositing Ti as an under layer and top layer.It was found that D-band corresponds to the disorder induced features generated in the graphitic planes of CNTs and G-band attributes to the graphitic phase corresponding the in-plane vibration of carbon atoms.