On the bonding structure of hydrogenated carbon nitrides grown by electron cyclotron resonance chemical vapour deposition: towards the synthesis of non-graphitic carbon nitrides

This work compares the composition and bonding structure of hydrogenated carbon nitride films (CNx:H) obtained by electron cyclotron resonance chemical vapour deposition (ECR-CVD) with those of hydrogen-free carbon nitrides (CNx) obtained by nitrogen ion beam assisted deposition (IBAD) of graphite.The composition and structure of the films was analysed by ion scattering techniques well suited to the detection of hydrogen, in addition to the more conventional infrared spectroscopy.The bonding structure was examined by X-ray absorption spectroscopy (XANES).The typical IBAD CNx films are graphitic with a N/C content below 0.3. However, the ECR-CVD films show a less graphitic bonding structure. The ECR-CVD films were synthesised in a conventional microwave ECR reactor (2.25 GHz, 875 Gauss, 250 W) using as precursor gases N2 and Ar in the reactor chamber, and CH4 directly in the deposition chamber.