Quantum Interference-Controlled Conductance Enhancement in Stacked Graphene-like Dimers

Li, Peihui and Hou, Songjun and Alharbi, Bader and Wu, Qingqing and Chen, Yijian and Zhou, Li and Gao, Tengyang and Li, Ruihao and Yang, Lan and Chang, Xinyue and Dong, Gang and Liu, Xunshan and Decurtins, Silvio and Liu, Shi-xia and Hong, Wenjing and Lambert, Colin and Jia, Chuangcheng and Guo, Xuefeng (2022) Quantum Interference-Controlled Conductance Enhancement in Stacked Graphene-like Dimers. Journal of the American Chemical Society, 144 (34). 15689–15697. ISSN 0002-7863

Text (3-Dimer-JACS-Main Text-0718-1-With mark)
3_Dimer_JACS_Main_Text_0718_1_With_mark.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (1MB)

Abstract

Stacking interactions are of significant importance in the fields of chemistry, biology, and material optoelectronics because they determine the efficiency of charge transfer between molecules and their quantum states. Previous studies have proven that when two monomers are π-stacked in series to form a dimer, the electrical conductance of the dimer is significantly lower than that of the monomer. Here, we present a strong opposite case that when two anthanthrene monomers are π-stacked to form a dimer in a scanning tunneling microscopic break junction, the conductance increases by as much as 25 in comparison with a monomer, which originates from a room-temperature quantum interference. Remarkably, both theory and experiment consistently reveal that this effect can be reversed by changing the connectivity of external electrodes to the monomer core. These results demonstrate that synthetic control of connectivity to molecular cores can be combined with stacking interactions between their π systems to modify and optimize charge transfer between molecules, opening up a wide variety of potential applications ranging from organic optoelectronics and photovoltaics to nanoelectronics and single-molecule electronics.