Willke, Philip

[["dc.bibliographiccitation.firstpage","5110"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Nano Letters"],["dc.bibliographiccitation.lastpage","5115"],["dc.bibliographiccitation.volume","15"],["dc.contributor.author","Willke, Philip"],["dc.contributor.author","Amani, Julian Alexander"],["dc.contributor.author","Sinterhauf, Anna"],["dc.contributor.author","Thakur, Sangeeta"],["dc.contributor.author","Kotzott, Thomas"],["dc.contributor.author","Druga, Thomas"],["dc.contributor.author","Weikert, Steffen"],["dc.contributor.author","Maiti, Kalobaran"],["dc.contributor.author","Hofsaess, Hans"],["dc.contributor.author","Wenderoth, Martin"],["dc.date.accessioned","2018-11-07T09:53:46Z"],["dc.date.available","2018-11-07T09:53:46Z"],["dc.date.issued","2015"],["dc.description.abstract","We investigate the structural, electronic, and transport properties of substitutional defects in SiC-graphene by means of scanning tunneling microscopy and magnetotransport experiments. Using ion incorporation via ultralow energy ion implantation, the influence of different ion species (boron, nitrogen, and carbon) can directly be compared. While boron and nitrogen atoms lead to an effective doping of the graphene sheet and can reduce or raise the position of the Fermi level, respectively, C-12(+) carbon ions are used to study possible defect creation by the bombardment. For low-temperature transport, the implantation leads to an increase in resistance and a decrease in mobility in contrast to undoped samples. For undoped samples, we observe in high magnetic fields a positive magnetoresistance that changes to negative for the doped samples, especially for B-11(+)- and C-12(+)-ions. We conclude that the conductivity of the graphene sheet is lowered by impurity atoms and especially by lattice defects, because they result in weak localization effects at low temperatures."],["dc.identifier.doi","10.1021/acs.nanolett.5b01280"],["dc.identifier.isi","000359613700039"],["dc.identifier.pmid","26120803"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36396"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","1530-6992"],["dc.relation.issn","1530-6984"],["dc.title","Doping of Graphene by Low-Energy Ion Beam Implantation: Structural, Electronic, and Transport Properties"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","166401"],["dc.bibliographiccitation.issue","16"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","128"],["dc.contributor.author","Pramanik, Arindam"],["dc.contributor.author","Thakur, Sangeeta"],["dc.contributor.author","Singh, Bahadur"],["dc.contributor.author","Willke, Philip"],["dc.contributor.author","Wenderoth, Martin"],["dc.contributor.author","Hofsäss, Hans"],["dc.contributor.author","Di Santo, Giovanni"],["dc.contributor.author","Petaccia, Luca"],["dc.contributor.author","Maiti, Kalobaran"],["dc.date.accessioned","2022-06-01T09:39:25Z"],["dc.date.available","2022-06-01T09:39:25Z"],["dc.date.issued","2022"],["dc.description.sponsorship"," Department of Atomic Energy, Government of India"],["dc.description.sponsorship"," Elettra-Sincrotrone Trieste"],["dc.description.sponsorship"," Board of Research in Nuclear Sciences"],["dc.identifier.doi","10.1103/PhysRevLett.128.166401"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/108470"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-572"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.rights.uri","https://link.aps.org/licenses/aps-default-license"],["dc.title","Anomalies at the Dirac Point in Graphene and Its Hole-Doped Compositions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","111605"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Applied Physics Letters"],["dc.bibliographiccitation.volume","105"],["dc.contributor.author","Willke, Philip"],["dc.contributor.author","Amani, Julian Alexander"],["dc.contributor.author","Thakur, S."],["dc.contributor.author","Weikert, Steffen"],["dc.contributor.author","Druga, T."],["dc.contributor.author","Maiti, Kalobaran"],["dc.contributor.author","Hofsaess, H."],["dc.contributor.author","Wenderoth, Martin"],["dc.date.accessioned","2018-11-07T09:35:13Z"],["dc.date.available","2018-11-07T09:35:13Z"],["dc.date.issued","2014"],["dc.description.abstract","We perform a structural analysis of nitrogen-doped graphene on SiC(0001) prepared by ultra low-energy ion bombardment. Using scanning tunneling microscopy, we show that nitrogen atoms are incorporated almost exclusively as graphitic substitution in the graphene honeycomb lattice. With an irradiation energy of 25 eV arid a tluence of approximately 5 x 10(14) cm(-2), we achieve a nitrogen content of around 1%. By quantitatively comparing the position of the N-atoms in the topography measurements with simulated random distributions, we find statistically significant short-range correlations. Consequently, we are able to show that the dopants arrange preferably at lattice sites given by the 6 x 6-reconstruction of the underlying substrate. This selective incorporation is most likely triggered by adsorbate layers present during the ion bombardment. This study identifies low-energy ion irradiation as a promising method for controlled doping in epitaxial graphene. (C) 2014 AIP Publishing LLC."],["dc.identifier.doi","10.1063/1.4895801"],["dc.identifier.isi","000342995800024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32338"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1077-3118"],["dc.relation.issn","0003-6951"],["dc.title","Short-range ordering of ion-implanted nitrogen atoms in SiC-graphene"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]