title: Unconventional molecule-resolved current rectification in diamondoid-fullerene hybrids.
abstract: The unimolecular rectifier is a fundamental building block of molecular electronics. Rectification in single molecules can arise from electron transfer between molecular orbitals displaying asymmetric spatial charge distributions, akin to p-n junction diodes in semiconductors. Here we report a novel all-hydrocarbon molecular rectifier consisting of a diamantane-C60 conjugate. By linking both sp(3) (diamondoid) and sp(2) (fullerene) carbon allotropes, this hybrid molecule opposingly pairs negative and positive electron affinities. The single-molecule conductances of self-assembled domains on Au(111), probed by low-temperature scanning tunnelling microscopy and spectroscopy, reveal a large rectifying response of the molecular constructs. This specific electronic behaviour is postulated to originate from the electrostatic repulsion of diamantane-C60 molecules due to positively charged terminal hydrogen atoms on the diamondoid interacting with the top electrode (scanning tip) at various bias voltages. Density functional theory computations scrutinize the electronic and vibrational spectroscopic fingerprints of this unique molecular structure and corroborate the unconventional rectification mechanism.
authors.affiliation: 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Randel
authors.affiliation: 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Francis C
authors.initials: FC
authors.lastname: Niestemski
authors.affiliation: Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium.
authors.forename: Andrés R
authors.initials: AR
authors.lastname: Botello-Mendez
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Warren
authors.initials: W
authors.lastname: Mar
authors.affiliation: 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Georges
authors.initials: G
authors.lastname: Ndabashimiye
authors.affiliation: Institute of Information and Communication Technologies, Electronics and Applied Mathematics, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium.
authors.forename: Sorin
authors.initials: S
authors.lastname: Melinte
authors.affiliation: SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA.
authors.forename: Jeremy E P
authors.initials: JE
authors.lastname: Dahl
authors.affiliation: SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA.
authors.forename: Robert M K
authors.initials: RM
authors.lastname: Carlson
authors.affiliation: Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany.
authors.forename: Ekaterina D
authors.initials: ED
authors.lastname: Butova
authors.affiliation: 1] Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany [2] Department of Organic Chemistry, Kiev Polytechnic Institute, UA-03056 Kiev, Ukraine.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Fokin
authors.affiliation: Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Schreiner
authors.affiliation: Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Charlier
authors.affiliation: 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Hari C
authors.initials: HC
authors.lastname: Manoharan