非晶碳结构建模和电子结构的第一性原理研究

基于密度泛函理论，采用了一种更为精确的交换相关泛函OLYP(OPTX+LYP)，对密度范围从2.0到3.2 g/cm³的非晶碳进行结构建模. 模拟得到的5个碳网络结构无论从径向分布函数还是sp³含量都与实验符合得很好. 对非晶碳电子结构的研究表明费米能级附近的电子态密度主要是sp²碳原子的贡献. 随着密度的增加，sp³碳原子增加，费米能级附近的态密度越来越小. 小环结构增加了费米能级附近的电子态密度，缺陷态在费米能级形 关键词： 非晶碳 密度泛函理论 电子结构

Ab initio structural simulation and electronic structure of amorphous carbon

Within the framework of density-functional theory, a new and more accurate exchange correlation functional OLYP(OPTX+LYP)was used to simulate the structures of amorphous carbon at densities from 2.0 to 3.2 g/cm³. The radial distribution function and sp³ fraction of the five simulated carbon networks are in good agreement with experimental results. The calculated electronic structures indicate that the states near Fermi level are mainly contributed by sp² carbon atoms. The states near Fermi level have a decreasing trend with increasing density and increasing sp³ content. The small ring structure increases the density of states near Fermi level. The defects will give a peak at Fermi level, which strongly reduces the band gap.