Large Spatially Resolved Rectification in a Donor-Acceptor Molecular Heterojunction

Joseph A Smerdon; Noel C Giebink; Nathan P Guisinger; Pierre Darancet; Jeffrey R Guest

doi:10.1021/acs.nanolett.6b00171

Large Spatially Resolved Rectification in a Donor-Acceptor Molecular Heterojunction

Nano Lett. 2016 Apr 13;16(4):2603-7. doi: 10.1021/acs.nanolett.6b00171. Epub 2016 Mar 17.

Authors

Joseph A Smerdon¹, Noel C Giebink², Nathan P Guisinger³, Pierre Darancet³, Jeffrey R Guest³

Affiliations

¹ Jeremiah Horrocks Institute of Mathematics, Physics and Astronomy, University of Central Lancashire , Preston, PR1 2HE, United Kingdom.
² Department of Electrical Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
³ Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.

PMID: 26964012
DOI: 10.1021/acs.nanolett.6b00171

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.

Keywords: DFT; Pentacene; STM; STS; Schottky; fullerene; rectification.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.