摘要
利用密度泛函理论和非平衡格林函数方法,系统研究了正三角锯齿型石墨烯的电子输运特性.研究表明:正三角石墨烯的电流-电压(I-V)特性及整流效应与几何尺寸、边缘吸附原子的类型密切相关,在其边缘吸附H原子和S原子的情况下,小的正三角石墨烯有大的电流,但有小的整流比;改变边缘吸附原子的类型(用O原子替换H原子),电流增大,但其整流效应明显变低.分析表明,这种整流是由于正三角石墨烯前线轨道的空间分布不对称以及在正、负偏压下分子能级的非对称移动所致.我们的研究对于认识正三角石墨烯的基本物性(电子结构及器件应用)有重要意义.
Based on the density functional theory and the non-equilibrium Green＇s function method, the electronic transport properties of zigzag-edged triangular graphene were studied systematically. The results revealed that the current-voltage （I-V） characteristics and rectifying effects were closely related to the geometric size and the type of atoms terminated at the edges of triangular graphene, in the case of H- and S-terminated edges, a small triangular graphene had a large current but with a small rectifying ratio. Although the current increased, the rectifying behavior was lowered when H atoms at the edges of the structure were replaced by O atoms. Deeper analysis demonstrated that such a rectification was caused by the asymmetry in the spatial distribution of the frontier orbitals and an asymmetric movement on the molecular-level in triangular graphene under positive and negative biases. It is of great significance that our investigations develop a thorough understanding of the basic physical properties of a triangular graphene.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2012年第7期1701-1706,共6页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(61071015
61101009)
湖南省研究生科研创新项目(CX2011B367)
湖南省重点学科建设项目资助~~
关键词
正三角石墨烯
整流效应
电子输运特性
密度泛函理论
非平衡格林函数方法
Triangular graphene
Rectifying effect
Electronic transport property
Density functional theory
Non-equilibrium Green＇s function method
