title: Large Spatially Resolved Rectification in a Donor-Acceptor Molecular Heterojunction.
abstract: We demonstrate that rectification ratios (RR) of ≳250 (≳1000) at biases of 0.5 V (1.2 V) are achievable at the two-molecule limit for donor-acceptor bilayers of pentacene on C60 on Cu using scanning tunneling spectroscopy and microscopy. Using first-principles calculations, we show that the system behaves as a molecular Schottky diode with a tunneling transport mechanism from semiconducting pentacene to Cu-hybridized metallic C60. Low-bias RRs vary by two orders-of-magnitude at the edge of these molecular heterojunctions due to increased Stark shifts and confinement effects.
authors.affiliation: Jeremiah Horrocks Institute of Mathematics, Physics and Astronomy, University of Central Lancashire , Preston, PR1 2HE, United Kingdom.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Smerdon
authors.affiliation: Department of Electrical Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Noel C
authors.initials: NC
authors.lastname: Giebink
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Guisinger
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Pierre
authors.initials: P
authors.lastname: Darancet
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Guest
keywords: DFT; Pentacene; STM; STS; Schottky; fullerene; rectification