title: Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers.
abstract: Self-assembled monolayers (SAMs) are widely used in a variety of emerging applications for surface modification of metals and oxides. Here, we demonstrate a new type of molecular self-assembly: the growth of organosilane SAMs at the surface of organic semiconductors. Remarkably, SAM growth results in a pronounced increase of the surface conductivity of organic materials, which can be very large for SAMs with a strong electron-withdrawing ability. For example, the conductivity induced by perfluorinated alkyl silanes in organic molecular crystals approaches 10(-5) S per square, two orders of magnitude greater than the maximum conductivity typically achieved in organic field-effect transistors. The observed large electronic effect opens new opportunities for nanoscale surface functionalization of organic semiconductors with molecular self-assembly. In particular, SAM-induced conductivity shows sensitivity to different molecular species present in the environment, which makes this system very attractive for chemical sensing applications.
authors.affiliation: Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA. podzorov@physics.rutgers.edu
authors.forename: M F
authors.initials: MF
authors.lastname: Calhoun
authors.forename: J
authors.initials: J
authors.lastname: Sanchez
authors.forename: D
authors.initials: D
authors.lastname: Olaya
authors.forename: M E
authors.initials: ME
authors.lastname: Gershenson
authors.forename: V
authors.initials: V
authors.lastname: Podzorov