物理化学学报 >> 2010, Vol. 26 >> Issue (10): 2686-2690.doi: 10.3866/PKU.WHXB20101012

催化和表面结构 上一篇    下一篇

隧道结电场辅助下叔丁胺分子在Cu(111) 表面跳跃

许逾群, 仉君, 袁秉凯, 邓珂, 杨蓉, 裘晓辉   

  1. 国家纳米科学中心, 北京100190
  • 收稿日期:2010-06-13 修回日期:2010-07-15 发布日期:2010-09-27
  • 通讯作者: 裘晓辉 E-mail:xhqiu@nanoctr.cn
  • 基金资助:

    国家重点基础研究发展计划项目(973)(2006CB921502)和中国科学院知识创新工程项目(KJCX2-YW-M04)资助

Electric Field Assisted Hopping of Tert-Butylamine on Cu(111) Surface

XU Yu-Qun, ZHANG Jun, YUAN Bing-Kai, DENG Ke, YANG Rong, QIU Xiao-Hui   

  1. National Center for Nanoscience and Technology, Beijing 100190, P. R. China
  • Received:2010-06-13 Revised:2010-07-15 Published:2010-09-27
  • Contact: QIU Xiao-Hui E-mail:xhqiu@nanoctr.cn
  • Supported by:

    The project was supported by the National Key Basic Research Programof China (973) (2006CB921502) and Knowledge Innovation Programof the Chinese Academy of Sciences (KJCX2-YW-M04).

摘要:

采用扫描隧道显微镜(STM) 于78K 研究了单个叔丁胺分子在Cu(111) 表面的横向跃迁现象. 研究发现叔丁胺分子的跳跃几率随隧道电流的增加而线性增加, 这表明该过程是单电子激发过程; 在不同极性的隧道结电场作用下, 叔丁基胺分子跳跃行为发生的几率不同, 这种现象可以用电场辅助的扩散过程解释. 在不同极性电场作用下叔丁胺分子在Cu(111) 表面的吸附能和扩散势垒不同, 从而表现出不同的跳跃几率.

关键词: 扫描隧道显微镜, 单分子, 跳跃现象, 电子激发, 隧道结电场

Abstract:

The lateral hopping of tert-butylamine (t-BA) molecules ona Cu(111) surface was studied by scanning tunneling microscopy (STM) at 78 K. The hopping probabilities of the molecules in the tunneling junction were found to depend linearly on the applied tunneling current, indicating a single electron-induced process. Hopping probabilities under an electric field of opposite polarity was found to be different. This non-equivalence is attributed to an electric field assisted diffusion where the adsorption energy and the diffusion barrier of the t-BA molecule are different when the polar molecule is subjected to opposite electric fields.

Key words: Scanning tunneling microscope, Single molecule, Hopping phenomenon, Electronic excitation, Electric field in a tunneling junction

MSC2000: 

  • O641