Projects per year
Abstract
π-conjugated organic molecules tend to adsorb in a planar configuration on graphene irrespective of their charge state. In contrast, here we demonstrate charging-induced strong structural relaxation of tetrafluorotetracyanoquinodimethane (F4TCNQ) on epitaxial graphene on Ir(111) (G/Ir(111)). The work function modulation over the graphene moiré unit cell causes site-selective charging of F4TCNQ. Upon charging, the molecule anchors to the face-centered cubic sites of the G/Ir(111) moiré through one or two cyano groups. The reaction is reversible and can be triggered on a single molecule by moving it between different adsorption sites. We introduce a model taking into account the trade-off between tilt-induced charging and reduced van der Waals interactions, which provides a general framework for understanding charging-induced structural relaxation on weakly interacting substrates. In addition, we argue that the partial sp3 rehybridization of the underlying graphene and the possible bonding mechanism between the cyano groups and the graphene substrate are also relevant for the complete understanding of the experiments. These results provide insight into molecular charging on graphene, and they are directly relevant for potential device applications where the use of molecules has been suggested for doping and band structure engineering.
Original language | English |
---|---|
Pages (from-to) | 4960-4968 |
Number of pages | 9 |
Journal | ACS Nano |
Volume | 11 |
Issue number | 5 |
DOIs | |
Publication status | Published - 23 May 2017 |
MoE publication type | A1 Journal article-refereed |
Keywords
- DFT
- epitaxial graphene
- FTCNQ
- Ir(111)
- Kondo effect
- self-assembly
- STM
Fingerprint Dive into the research topics of 'Charge-Transfer-Driven Nonplanar Adsorption of F<sub>4</sub>TCNQ Molecules on Epitaxial Graphene'. Together they form a unique fingerprint.
Projects
- 4 Finished
-
Atomically precise materials for future devices
Huda, M. N., Liljeroth, P. & Kumar, A.
01/10/2016 → 30/09/2018
Project: Academy of Finland: Other research funding
-
COMP: Centre of Excellence in Computational Nanoscience
Järvi, J., Li, J., Todorovic, M., Rinke, P. & Dvorak, M.
01/01/2016 → 31/12/2017
Project: Academy of Finland: Other research funding
-
Centre of Excellence in Low Temperature Quantum Phenomena and Devices
Liljeroth, P., Shawulienu, K. & Kumar, A.
01/01/2015 → 31/01/2018
Project: Academy of Finland: Other research funding
Equipment
-
-
OtaNano - Nanomicroscopy Center
Janne Ruokolainen (Manager)
Department of Applied PhysicsFacility/equipment: Facility
-