The rectifying performance of the multibiphenyl with different end groups: A density functional study

• Published in: Journal of applied physics 2011-03, Vol.109 (6), p.063712-063712-5
• Main Authors: Deng, Xiaoqing, Zhang, Zhenhua, Zhou, Jicheng, Tang, Guiping
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.3561482

We investigated the rectifying properties of the multibiphenyl connected to two Au electrodes based on the nonequilibrium Green's function method combined with the density functional theory. It has been found that the number of benzenes and the type of end groups have distinct influences on rectifying performance of such devices. For the four (five)-benzene system connected with Au electrodes by S-Au bond, we can observe the rectifying performance. While for the six-benzene system, the rectifying behavior is more obvious. When the left end benzene is replaced by pyrimidine, the rectifying effect is weakened. When this substitute is pyridine, however, the rectifying behavior changes clearly as compared with the previous two cases. The detailed analysis demonstrates that the highest occupied molecular orbital resonance changing with the applied bias contributes to the obvious asymmetry of current-voltage characteristics.