Microstructural and electrical properties of amorphous carbon nitride

Optical and electrical properties of amorphous carbon nitride (a-CN) have been investigated on films deposited by reactive R.F. sputtering method with a graphite target. Two series of a-CN samples were prepared using respectively the nitrogen (N2) or mixture of nitrogen and argon (Ar) as reactant gaz. In the two types of samples, the optical absorption increases with the target voltage bias and shifts to low energy. In the visible and near ultra violet range, the optical transitions are governed by the π and π∗ electronic state distributions, related to sp2 and sp1 hybridized C and N atoms. Specific lonepair electronic states arise from groups (CN) with sp1 hybridized C atoms, may form CN triple bonds or —NCN— longer chains. Photoluminescence (PL) intensity depends on the microstructure in films but the PL peak does not change of its position at 1.85 eV. The effect of nitrogen and target voltage bias on the optical and electrical properties was discussed in a-CN samples. The electrical properties of Schottky structures based on a-CN materials were characterized.