Optical characterization of amorphous hydrogenated carbon films

Abstract Photoluminescence, Raman scattering, and infrared absorption spectroscopies were employed to study the properties of a-C:H thin films deposited under constant pressure conditions. The films examined in the present work were prepared with and without the presence of nitrogen in the deposition process gases. Low temperature photoluminescence spectra revealed new emission bands at 564 nm and 637 nm for the nitrogen doped films. Three Raman scattering lines are observed in the nitrogen doped and annealed films. The Raman scattering spectra of the annealed films suggest the presence of microcrystalline graphite inclusions in the bulk of the film. Additional infrared absorption data support the Raman results. These observations agree with the proposed cluster model of a-C:H films consisting of sp2 and sp3 bonding structures.