Tabitha A. Amollo1, Qi Hua Fan2
1Egerton University, Nakuru, Kenya
2Michigan State University, East Lansing, MI
Diamond like carbon (DLC) is an amorphous form of carbon consisting of sp2 and sp3 hybridized carbon atoms and hydrogen. It is characterized by unique properties which suit it as a protective coating in various applications. DLC thin films are commonly produced by plasma-enhanced chemical vapor deposition (PECVD). This study reports the growth of hydrogenated DLC thin films using a novel broad beam plasma source, which enables simultaneous ion bombardments to the surface atoms and produces dense films at room temperature. A key advantage of the broad beam ion source is that it can independently control the ion flux and ion energy (20-200 eV) and thus, DLC film microstructures and properties. The film growth rates were proportional to the ion flux density, which in turn was proportional to the plasma density. An optimum ion energy of ~120 eV was identified. The DLC films exhibited high optical transmittance of 90% from the visible to the infrared region. The optical band gaps were in the range of 2.20-2.28 eV. The prepared films exhibited a density of 1.905 g/cm3 and Young’s modulus of 75 GPa. A potential application of such DLC films is as moisture barrier coatings on plastics, which require low-temperature processing.