Au电极作用下C_(60)、2C_(60)与4C_(60)富勒烯分子的电子传输特性

Electronic Transmission of C_(60),2C_(60) and 4C_(60) Fullerene Molecules

采用扩展的Hückel方法与格林函数方法,研究了Au电极作用下,C60富勒烯、2C60和4C60聚合体分子的电子结构与导电性,并对它们的电子结构与电子输运特性进行了对比。研究结果表明,C60、2C60或4C60富勒烯分子与Au电极”接触”后,其HOMO、LUMO间的能隙减小;C60、2C60或4C60分子与Au电极之间的结合既有共价键的成分,又有离子键的成分,其中,C60、4C60分子与Au电极结合的离子键特征更为明显;三种富勒烯分子的电子输运性能依次具有C60>2C60>4C60分子的顺序。

Extend Hückel method of the first principle, as well as Green＇ s-function based method, was used to analyze the electronic structure and electronic transmission of Au electrode-C60, 2C60 or 4C60 fullerene molecule-Au electrode systems. The analytical results show that, （1） due to the intervention of Au electrodes, the electronic structures of the C60, 2C60 and 4C60 molecules are changed significantly, and their energy-level gaps between LUMO and HOMO narrow; （2） the coalescent between C60 , 2C60 or 4C60 fullerene molecule and Au electrodes includes not only covalent bond but also electrovalent bond; and （3） the conductivities of the three electrode-fullerene molecule-Au electrode systems conform to the order of C60 〉 2C60 〉 4C60. The relative conclusions in this paper are beneficial to go further deep into electronic transmission of carbon fullerenes.