Stoichiometry and infrared absorption of amorphous a-C1-xNx:H carbon nitride films

Stoichiometry, bonding configurations and structural properties of plasma-deposited hydrogen-rich amorphous carbon nitride a-C1-xNx:H (0<x<0.20) films have been investigated using infrared and Raman vibrational spectroscopies, along with x-ray photoemission spectroscopy at the C and N K-edges. With increasing N incorporation in a-C1-xNx:H, the total H content decreases slightly and C-H vibrations are progressively replaced by N-H vibrations. The dominant bonding configuration is C=N throughout the composition range, although C=N and C-N saturate above 10 N at. %, and C=N configurations steadily increase throughout the stoichiometry range. A strong conjugation of imine (C=N) and nitrile (C=N) groups with aromatic rings is evidenced while the Raman signature of the sp(2) C phase indicates an increase in the D to G peak intensity ratio, related to some ordering of the sp(2) clustered phase. (C) 2004 American Institute of Physics.