title: Stabilization of graphene nanopore.
abstract: Graphene is an ultrathin, impervious membrane. The controlled introduction of nanoscale pores in graphene would lead to applications that involve water purification, chemical separation, and DNA sequencing. However, graphene nanopores are unstable against filling by carbon adatoms. Here, using aberration-corrected scanning transmission electron microscopy and density-functional calculations, we report that Si atoms stabilize graphene nanopores by bridging the dangling bonds around the perimeter of the hole. Si-passivated pores remain intact even under intense electron beam irradiation, and they were observed several months after the sample fabrication, demonstrating that these structures are intrinsically robust and stable against carbon filling. Theoretical calculations reveal the underlying mechanism for this stabilization effect: Si atoms bond strongly to the graphene edge, and their preference for tetrahedral coordination forces C adatoms to form dendrites sticking out of the graphene plane, instead of filling the nanopore. Our results provide a novel way to develop stable nanopores, which is a major step toward reliable graphene-based molecular translocation devices.
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831;Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235; leej2@ornl.gov chisholmmf@ornl.gov.
authors.forename: Jaekwang
authors.initials: J
authors.lastname: Lee
authors.affiliation: Shenyang National Laboratory for Material Science, Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China; and.
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831;
authors.forename: Wu
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235;Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Pennycook
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831;Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235;
authors.forename: Sokrates T
authors.initials: ST
authors.lastname: Pantelides
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831;Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 leej2@ornl.gov chisholmmf@ornl.gov.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Chisholm
mesh_terms: D002244:Carbon / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D008956:Models, Chemical; D058608:Nanopores / Q000648:ultrastructure*; D017422:Sequence Analysis, DNA / Q000379:methods / Q000639:trends; D012825:Silicon / Q000737:chemistry*
chemical_list: D002244:Carbon; D006108:Graphite; D012825:Silicon
keywords: STEM imaging; density-functional theory; nanopore stabilization; self-healing process