title: Scanning tunneling microscopy of self-assembled phenylene ethynylene oligomers on Au(111) substrates.
abstract: In this paper, we report the self-assembly, electrical characterization, and surface modification of dithiolated phenylene-ethynylene oligomer monolayers on a Au(111) surface. The self-assembly was accomplished by thiol bonding the molecules from solution to a Au(111) surface. We have confirmed the formation of self-assembled monolayers by scanning tunneling microscopy (STM) and optical ellipsometry, and have studied the kinetics of film growth. We suggest that self-assembled phenylene ethynylene oligomers on Au(111) surfaces grow as thiols rather than as thiolates. Using low-temperature STM, we collected local current-voltage spectra showing negative differential resistance at 6 K.
authors.affiliation: Mikroelektronik Centret (MIC), Technical University of Denmark, Bldg. 345 East, DK-2800 Lyngby, Denmark. walzer@iapp.de
authors.forename: Karsten
authors.initials: K
authors.lastname: Walzer
authors.forename: Eike
authors.initials: E
authors.lastname: Marx
authors.forename: Neil C
authors.initials: NC
authors.lastname: Greenham
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Less
authors.forename: Paul R
authors.initials: PR
authors.lastname: Raithby
authors.forename: Kurt
authors.initials: K
authors.lastname: Stokbro