Institute of Computational and Theoretical Studies
We use cryogenic scanning tunneling microscopy/spectroscopy and density-functional theory calculations to inspect the modulation of electronic states of aromatic molecules. The molecules are self-assembled on a Cu(111) surface forming molecular networks in which the molecules are in different contact configurations, including laterally-coupled to different numbers of coordination bonds and vertically-adsorbed at different heights above the substrate. We quantitatively analyze the molecular states and find that a delocalized empty molecular state is modulated by these multiple contacts in a cooperative manner: its energy is down-shifted by ~0.16 eV for each additional lateral contact and by ~0.1 eV as the vertical molecule-surface distance is reduced by 0.1 Å in the physisorption regime. We also report that in a molecule-metal-molecule system the bridging metal can mediate the electronic states of the two molecules.
Physical Review Letters
American Physical Society
First Page (page number)
Last Page (page number)
Wang, Weihua, Xingqiang Shi, Shiyong Wang, Jun Liu, Andre M. Van Hove, Pei Nian Liu, Rui-Qin Zhang, and N. Lin. "Cooperative modulation of electronic structures of aromatic molecules coupled to multiple metal contacts." Physical Review Letters 110 (2013): 046802-1-046802-5.