Open AccessEffects of end groups on the rectifying performance in D-B-A molecular rectifiers
Author(s) -
Chao Guo,
Zhenhua Zhang,
Jinbo Pan,
Junjun Zhang
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.117303
Subject(s) - delocalized electron , molecular orbital , density functional theory , molecule , chemical physics , materials science , coupling (piping) , molecular electronics , function (biology) , physics , quantum mechanics , evolutionary biology , metallurgy , biology
Using the density-functional theory and the non-equilibrium Greens function method, we investigate the electronic transport properties and rectifying performances of four different molecular devices based on different end groups from the same D-B-A molecule. The results show that the end groups can significantly affect the rectifying performances of such molecular rectifiers, because the end groups can influence the coupling effects between the molecule and the electrodes, thus changing the delocalization of molecular orbitals, and further changing their transport properties and rectifying performances. More interestingly, it is found that the rectifying directions and working mechanism for all of our studied systems are in disagreement with ones proposed originally by Aviram and Ratner. This property can be rationalized through the asymmetric shift of molecular levels under biases of different polarities.