Many-body dispersion effects on the binding of TCNQ and F4-TCNQ with graphene. (January 2017)

• Record Type: Journal Article
• Authors: Yang, Sha; Jiang, Yingda; Li, Shuang; Liu, Wei
• Is Part Of: Carbon. Volume 111(2017)
• Page Start: 513
• Page End: 518
• Publication Date: 2017-01
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2016.10.024
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Predictive modeling and understanding of binding of organic molecule-decorated graphene is an essential prerequisite for tuning their electronic and magnetic properties. Many-body dispersion (MBD) interactions are known to contribute significantly to the binding of condensed matters, but the role of MBD energy in self-assembled organic monolayers on epitaxial graphene remains largely unexplored. Here, by using the state-of-the-art DFT + MBD method, we for the first time investigate model π - π adsorption systems that are composed of two typical acceptor molecules, TCNQ and F4-TCNQ, and graphene sheets. The computed binding energies from the DFT + MBD method are consistently smaller than those from the pairwise-based van der Waals (vdW) inclusive method, such as DFT + vdW, due to the accurate capture of both electrodynamic screening and many-body effects in the former case. Notably, many-body effects contribute more to the low-coverage adsorption systems than they do when the substrate is highly covered by the adsorbates. This somewhat counter-intuitive result is attributed to the fact that each molecule contributes less to the polarization of the hybrid interface at high coverage. Graphical abstract: