物理化学学报 >> 2012, Vol. 28 >> Issue (07): 1701-1706.doi: 10.3866/PKU.WHXB201204172

理论与计算化学 上一篇    下一篇

正三角锯齿型石墨烯的电子输运特性

张俊俊, 张振华, 郭超, 李杰, 邓小清   

  1. 长沙理工大学物理与电子科学学院, 长沙 410114
  • 收稿日期:2012-01-12 修回日期:2012-04-16 发布日期:2012-06-07
  • 通讯作者: 张振华 E-mail:scuzzh@163.com
  • 基金资助:

    国家自然科学基金(61071015, 61101009), 湖南省研究生科研创新项目(CX2011B367)及湖南省重点学科建设项目资助

Electronic Transport Properties for a Zigzag-Edged Triangular Graphene

ZHANG Jun-Jun, ZHANG Zhen-Hua, GUO Chao, LI Jie, DENG Xiao-Qing   

  1. School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, P. R. China
  • Received:2012-01-12 Revised:2012-04-16 Published:2012-06-07
  • Contact: ZHANG Zhen-Hua E-mail:scuzzh@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (61071015, 61101009), Hunan Provincial Innovation Foundation for Postgraduate, China (CX2011B367), and Construct Program of the Key Discipline in Hunan Province, China.

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.

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

Abstract:

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 Hand 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.

Key words: Triangular graphene, Rectifying effect, Electronic transport property, Density functional theory, Non-equilibrium Green?s function method

MSC2000: 

  • O641