Density and capture radius of 'defects': quenching of the luminescent states in non-nitrogenated and nitrogenated amorphous carbon thin films

The properties of photoluminescence (PL) n nitrogenated and non-nitrogenated amorphous carbon films are discussed. Err phasis is given to nitrogenated films and their peculiarities. The role of oxygen, through structural relaxation, and of nitrogen, due to structural relaxation an I lone pairs, is discussed. A general correlation between the density of diamagnetic and paramagnetic 'defects' of different extensions and the quantum efficiency of PL is found. It is also shown that a-CN films can be divided in two categories, following their local structure and, in particular, the presence of voids, that lead to large scale oxygen contamination and stress release.