物理化学学报 >> 2006, Vol. 22 >> Issue (02): 161-166.doi: 10.3866/PKU.WHXB20060207

研究论文 上一篇    下一篇

Al-C60-Al分子结电子输运特性的第一性原理计算

黄飙 ; 张家兴; 李锐; 申自勇; 侯士敏; 赵兴钰; 薛增泉; 吴全德   

  1. 北京大学信息科学技术学院, 北京大学纳米器件物理与化学教育部重点实验室, 北京 100871
  • 收稿日期:2005-07-01 修回日期:2005-09-23 发布日期:2006-01-22
  • 通讯作者: 申自勇 E-mail:szy@ele.pku.edu.cn

First-principles Calculation of the Conductance of the Al-C60-Al Junction

HUANG Biao; ZHANG Jia-xing; LI Rui; SHEN Zi-yong; HOU Shi-min; ZHAO Xingyu; XUE Zeng-quan; WU Quan-de   

  1. Key Laboratory for the Physics and Chemistry of Nanodevices of Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, P.R. China
  • Received:2005-07-01 Revised:2005-09-23 Published:2006-01-22
  • Contact: SHEN Zi-yong E-mail:szy@ele.pku.edu.cn

摘要: 利用基于密度泛函理论的格林函数方法, 计算了Al-C60-Al分子结的电子输运特性. 考虑了C60分子在铝电极表面的原子结构弛豫, 计算结果表明共振传导是Al-C60-Al分子结电子输运的主要特征, 在费米能级附近的电导约为1.14G0 (G0=2e2/h). 投影态密度(PDOS)分析表明, Al-C60-Al分子结的电子输运主要通过C60分子的最低空分子轨道(LUMO)和次低空分子轨道(LUMO+1)进行. 讨论了C60分子和铝电极之间距离的变化对其电子输运特性的影响.

关键词: Al-C60-Al分子结, 电子输运, 密度泛函理论, 格林函数方法

Abstract: The conductance of an Al-C60-Al molecule junction is calculated using a density functional theory combined with Green′s function method. When the molecule is connected to the electrodes and allowed to relax, resonant conductance is the main feature of the transport properties of the Al-C60-Al molecule junction. The conductance around the Fermi level is determined to be about 1.14G0 (G0=2e2/h). Analysis of the density of states projected onto the frontier molecular orbitals of the C60 molecule shows that electron transport occurs primarily through the lowest unoccupied molecular orbital (LUMO) and the second lowest unoccupied molecular orbital (LUMO+1) of C60. The dependence of the junction conductance on the distance between the C60 molecule and the electrodes is also discussed.

Key words: Al-C60-Al molecule junction, Electron transport, Density functional theory, Green′s function method