化学学报 ›› 2004, Vol. 62 ›› Issue (1): 10-15. 上一篇    下一篇

研究论文

ET类分子导体3d轨道对晶体能带及导电性的影响

刘国群1, 雷虹2, 方奇1,3   

  1. 1. 山东大学晶体材料国家重点实验室, 济南, 250100;
    2. 山东大学信息科学与工程学院, 济南, 250100;
    3. 山东大学化学与化工学院, 济南, 250100
  • 投稿日期:2003-06-09 修回日期:2003-08-20 发布日期:2014-01-26
  • 通讯作者: 方奇 E-mail::E-mail:fangqi@icm.sdu.edu.cn
  • 基金资助:

    国家自然科学基金(No.20172034)和教育部高等学校骨干教师基金资助项目.

Influence of 3d Orbital on the Energy Band and Electrical Conductivity in ET-type Molecular Conductor

LIU Guo-Quna1, LEI Hongb2, FANG Qi1,3   

  1. 1. State Key Laboratory of Crystal Materials;
    2. School of Information Science and Engineering;
    3. School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100
  • Received:2003-06-09 Revised:2003-08-20 Published:2014-01-26

采用扩展休克尔-紧束缚方法(EHTB)研究了ET类分子导体[ET=bis-(ethylenedithio)-tetrathiafulvalene]的能带.讨论了硫原子3d轨道对能带结构的影响,添加3d轨道导致ET分子柱间的横向作用大为增强,并与纵向作用处于同一数量级,这一结论解释了晶体二维导电性的实验结果.计算得到(ET)2C3H5SO3·H2O, (ET)2HgCl3·TCE两个晶体的带隙分别为0.579, 0.572 eV,与实验得到的导电激活能0.319, 0.308 eV符合较好.

关键词: 能带结构, ET类分子导体, 导电性

Energy band of ET-type molecular conductors were calculated using the Extended Hückel-Tight Binding method (EHTB). The introducing of sulfur 3d orbitals to the EHTB calculation leads to a great enhancement of the transverse interactions between ET stacks. Consequently, the transverse and longitudinal interactions in the ET stacks have the same order of magnitude. The results could well explain the two-dimensional conductivity nature of this kind of molecular conductors. Calculated band gaps of the (ET)2C3H5SO3·H2O and (ET)2HgCl3·TCE crystals are 0.579 and 0.572 eV respectively, which were in good agreement with the experimental conductive activation energy 0.319 and 0.308 eV.

Key words: energy band structure, ET-type molecular conductor, electrical conductivity