Optical characterization of amorphous hydrogenated carbon films

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 p repared with and without the presence of nitrogen in the deposition process gases. Low temperature photoluminescence spectra revealed new emission ban ds at 564 nm and 637 nm for the nitrogen doped films. Three Raman scatterin g lines are observed in the nitrogen doped and annealed films. The Raman sc attering spectra of the annealed films suggest the presence of microcrystal line graphite inclusions in the bulk of the film. Additional infrared absor ption data support the Raman results. These observations agree with the pro posed cluster model of a-C:H films consisting of sp(2) and sp(3) beading st ructures. (C) 2000 Elsevier Science S.A. All rights reserved.