正三角锯齿型石墨烯的电子输运特性 - Ingenta Connect.PDF

物理化学学报(Wuli Huaxue Xuebao) July Acta Phys. -Chim. Sin . 2012, 28 (7), 1701-1706 1701 [Article] doi: 10.3866/PKU.WHXB201204172 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 (长沙理工大学物理与电子科学学院, 长沙410114) 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 中图分类号: O641 Electronic Transport Properties for a Zigzag-Edged Triangular Graphene ZHANG Jun-Jun ZHANG Zhen-Hua* GUO Chao LI Jie DENG Xiao-Qing (School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, P. R. China) Abstract: Based on the density functional theory and the non-equilibrium Greenʹs 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 rect