摘要
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3.2g/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成尖峰,使带隙大大降低.
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/cm^3 . The radial distribution function and sp^3 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 sp^2 carbon atoms. The states near Fermi level have a decreasing trend with increasing density and increasing sp^3 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.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第1期398-404,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:50602012)资助的课题~~
关键词
非晶碳
密度泛函理论
电子结构
amorphous carbon, density-functional theory, electronic structure
