title: Accurate determination of plasmonic fields in molecular junctions by current rectification at optical frequencies.
abstract: Current rectification, i.e., induction of dc current by oscillating electromagnetic fields, is demonstrated in molecular junctions at an optical frequency. The magnitude of rectification is used to accurately determine the effective oscillating potentials in the junctions induced by the irradiating laser. Since the gap size of the junctions used in this study is precisely determined by the length of the embedded molecules, the oscillating potential can be used to calculate the plasmonic enhancement of the electromagnetic field in the junctions. With a set of junctions based on alkyl thiolated molecules with identical HOMO-LUMO gap and different lengths, an exponential dependence of the plasmonic field enhancement on gap size is observed.
authors.affiliation: School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Rani
authors.initials: R
authors.lastname: Arielly
authors.forename: Ayelet
authors.initials: A
authors.lastname: Ofarim
authors.forename: Gilad
authors.initials: G
authors.lastname: Noy
authors.forename: Yoram
authors.initials: Y
authors.lastname: Selzer
mesh_terms: D004553:Electric Conductivity; D036103:Nanotechnology; D010316:Particle Size; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D013438:Sulfhydryl Compounds