Effect of Variation in Gas Composition on the Growth Density and Size of the Carbon Nanostructures Deposited by RF-PECVD

Abstract-A focus on synthesizing different types of two-dimensional Carbon nanostructures using Methane and Argon without catalyst has been conducted in Radio Frequency Plasma Enhanced Chemical Vapor Deposition. This study reports the variation in growth density, size and morphological characteristics of Carbon nanostructures by varying the gas compositions. Field Emission Scanning Electron Microcopy (FE-SEM) and Atomic Force Microscopy (AFM) studies shows the high percentage of Methane gas in the composition is directly proportional to the density and inversely proportional to the size of the nanostructure. We report that the concentration of Methane usually offers more carbon species or driving force for the growth of the two-dimensional carbon nanostructures. This process enables to increase the density and decreases the size of the nanostructures. The results of Raman spectroscopy show the typical carbon features at 1321,1571 and 2639cm-1 respectively. The intensity ratio of these two peaks ID/IG increases with increase in the Methane gas percentage in the composition indicates the nanocrystalline nature of two-dimensional carbon nanostructures with a large number of defects.