Molecular Self-Assembly in a Poorly Screened Environment: F4TCNQ on Graphene/BN.

Autor:	Tsai HZ; Department of Physics, University of California , Berkeley, California 94720, United States., Omrani AA; Department of Physics, University of California , Berkeley, California 94720, United States., Coh S; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Oh H; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Wickenburg S; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Son YW; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.; Korea Institute for Advanced Study , Seoul 130-722, Korea., Wong D; Department of Physics, University of California , Berkeley, California 94720, United States., Riss A; Department of Physics, University of California , Berkeley, California 94720, United States., Jung HS; Department of Physics, University of California , Berkeley, California 94720, United States., Nguyen GD; Department of Physics, University of California , Berkeley, California 94720, United States., Rodgers GF; Department of Physics, University of California , Berkeley, California 94720, United States., Aikawa AS; Department of Physics, University of California , Berkeley, California 94720, United States., Taniguchi T; National Institute for Materials Science , 1-1 Namiki, Tsukuba, 305-0044, Japan., Watanabe K; National Institute for Materials Science , 1-1 Namiki, Tsukuba, 305-0044, Japan., Zettl A; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.; Kavli Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Louie SG; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Lu J; Department of Physics, University of California , Berkeley, California 94720, United States.; Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.; Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546, Singapore., Cohen ML; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Crommie MF; Department of Physics, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.; Kavli Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Jazyk:	angličtina
Zdroj:	ACS nano [ACS Nano] 2015 Dec 22; Vol. 9 (12), pp. 12168-73. Date of Electronic Publication: 2015 Oct 28.
DOI:	10.1021/acsnano.5b05322
Abstrakt:	We report a scanning tunneling microscopy and noncontact atomic force microscopy study of close-packed 2D islands of tetrafluorotetracyanoquinodimethane (F4TCNQ) molecules at the surface of a graphene layer supported by boron nitride. While F4TCNQ molecules are known to form cohesive 3D solids, the intermolecular interactions that are attractive for F4TCNQ in 3D are repulsive in 2D. Our experimental observation of cohesive molecular behavior for F4TCNQ on graphene is thus unexpected. This self-assembly behavior can be explained by a novel solid formation mechanism that occurs when charged molecules are placed in a poorly screened environment. As negatively charged molecules coalesce, the local work function increases, causing electrons to flow into the coalescing molecular island and increase its cohesive binding energy.
Databáze:	MEDLINE
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