Synthesis and Analysis of Thin Conducting Pyrolytic Carbon Films

Abstract

We report on an adjustable process for chemical vapour deposition of thin films of pyrolytic carbon on inert substrates using an acetylene feedstock. Through modification of the reaction parameters control over film thickness and roughness is attained. These conducting films can be deposited in a conformal fashion, with thicknesses as low as 5 nm and a surface roughness of less than 1 nm. The highly reliable, cost effective and scalable synthesis may have a range of applications in information and communications technology and other areas. Raman and X-ray photoelectron spectroscopies, as well as high resolution transmission electron microscopy are used to investigate the composition and crystallinity of these films. The suitability of these films as electrodes in transparent conductors is assessed through a combination of absorbance and sheet resistance measurements. The films have a resistivity of ∼ 2 × 10-5 Ωm but absorb strongly in the visible range. The electrochemical properties of the films are investigated and are seen to undergo a marked improvement following exposure to O2 or N2 plasmas, making them of interest as electrochemical electrodes.