富勒烯C_(74)分子的电子传导特性

Electronic Transmission Characteristics of Fullerene C_(74) Molecule

采用密度泛函理论和非平衡Green函数的Tight-Binding方法,对C74富勒烯分子及其连接Au电极构成的C74分子器件的电子结构和电子传导特性进行了理论研究。得出了电子通过C74分子器件的传输谱、态密度及C74分子的分子轨道能级,结果显示C74分子的传输谱和态密度有明显的对应性,且电子的传导概率随电子的入射能量变化而变化。用同样的方法研究了在有限偏压下C74分子的I-V曲线及其电导,其中C74分子的I-V曲线表现出近似的线性特征,电导随电压的变化而出现非周期性的振荡特性,这说明C74分子具有良好的电子传导特性。

The electronic structure and electronic transmission characteristics of C74 molecule bridge between Au electrodes and C74 molecule were theoretically researched by using the density functional theory and Tight-Binding method of the nonequilibrium Green＇s function.The transport spectra and the densities of states which electrons transmit through C74 molecule bridge and the orbital energy levels of C74 were obtained.The result shows that the peaks of the transport spectra are corresponding with the densities of states obviously.The electron transmission pro-bability changes along with the incident energy of the electrons.By the same way,the I-V curve and the conductance of C74 molecule were researched at the finite bias.The I-V curve of C74 molecule represents approximative linear characteristics,and the variation of the conductance of C74 molecule with the change in voltage leads to the characteristics of the non-periodic oscillation,which indicates that the C74 molecule has an excellent electric transmission characteristic.