First principles studies of nitrogen doped tetrahedral amorphous carbon

The microstructures and electronic structures of nitrogen doped tetrahedral amorphous carbon (ta-C:N) have been simulated and investigated using molecular dynamics within the framework of density functional theory. There are no obvious relation between the coordination of nitrogen and the density of ta-C:N. The most common form of nitrogen bonding was found to be three coordinated. Two coordinated and a small quantity of four coordinated nitrogen atoms were also found. The addition of nitrogen caused a big increase in the sp² fraction of carbon. The states near Fermi level increased in density as the contents of nitrogen atoms increased. Fermi level was not found to shift obviously.