掺氮四面体非晶碳的第一性原理研究

采用基于第一性原理的分子动力学方法对掺氮四面体非晶碳进行结构建模,并对其显微结构和电子结构进行了研究. 氮在非晶碳网络中的配位形态与密度没有明显关系,主要是以三配位形态存在,其次是两配位,四配位氮的比例很小. 掺氮后碳网络结构sp²含量大大增加,随着氮含量的增加,费米能级附近态密度增加. 氮掺入后并未使费米能级发生明显移动.关键词：掺氮四面体非晶碳第一性原理密度泛函理论电子结构

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.