Department of Physics, Panjab University, Chandigarh, India

TPSC seminar

Date and time: 26 May 2014 (Monday), 4:00 pm
Venue: Seminar Hall

Title: Role of plasma on the growth and field emission properties of metallic carbon nanotubes

Speaker: Prof. Suresh C. Sharma, Department of Applied Physics, Delhi Technological University, Delhi

Abstract: Carbon nanotubes (CNTs) are currently attractive materials for a diverse range of applications because of their extraordinary mechanical and electrical properties. Their application has already been demonstrated in field emission displays, nanoscale electronic devices, biosensors and hydrogen storage mediums. The field emission properties of carbon nanotubes are an important field of study because they give very high values of current density as compared to the already existing field emission devices. The effect of various factors such as plasma parameters, substitutional atoms, dimensional effects, anode-cathode distance etc. on field emission from CNT has also been extensively studied. The present talk will cover the plasma production and the role of plasmas i.e. plasma densities and temperatures on the growth (without a catalyst), structure and field emission properties of spherical metallic CNT tip and cylindrical metallic CNT surfaces. A theoretical model of charge neutrality, including kinetics of electrons, positively charged ions and neutral atoms and the energy balance of the various species in plasma have been developed. Numerical calculations of the radius of spherical CNT tip and cylindrical CNT surfaces for different CNT number density and plasma parameters (plasma densities and temperatures) have been carried out for the typical glow discharge plasma parameters. It is found that on increasing the CNT number density and plasma parameters, the radius of spherical CNT tip and cylindrical CNT surfaces decreases and consequently the field emission of electrons from spherical CNT tip and cylindrical CNT surfaces increases.

About the speaker: Prof. Sharma has joined the Department of Physics, IIT Delhi, as a Senior Research Assistant in the year 1990 and worked till 1996. He was awarded the Young Scientist project as a principal Investigator by the Department of Science and Technology (DST), Govt. of India for a two year duration (1997-99). He was a Monbusho Fellow with Ehime University, Japan, from October 1997 to March 1999. In addition, he has been a JSPS Postdoctoral Fellow/Visiting Researcher from May 2004 to October 2005 with the Center for Atomic and Molecular Technologies (CAMT), Osaka University, Japan. Besides, he was awarded pool officership by CSIR, Govt. of India for 3 years duration (1999-2002) and worked in the Department of Physics and Astrophysics, University of Delhi from April 1999 to January 2002. Recently, he has been sanctioned a major research project on Graphenes under SERB by DST, Govt. of India for a duration of 3 years. Currently, he is working as Professor and Head with the Department of Applied Physics, Delhi Technological University (DTU), Delhi. He has published 83 research papers in International Journals and Proceedings of International Conferences. Dr. Sharma is a reviewer of various Journal of International repute. Prof. Sharma is a member of several professional societies including the Indian Chapter of the International Center for Theoretical Physics (ICTP, Trieste, Italy), the Plasma Science Society of India, and the Indian Society for Technical Education, New Delhi, India.