Fluorinated benzalkylsilane molecular rectifiers

We report on the synthesis and electrical properties of nine new alkylated silane self-assembled monolayers (SAMs) – (EtO)3Si(CH2)nN = CHPhX where n = 3 or 11 and X = 4-CF[subscript 3], 3,5-CF[subscript 3], 3-F-4-CF[subscript 3], 4-F, or 2,3,4,5,6-F, and explore their rectification behavior in relat...

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Bibliographic Details
Main Authors: Lamport, Zachary A., Broadnax, Angela D., Harrison, David, Barth, Katrina J., Mendenhall, Lee, Hamilton, Clayton T., Guthold, Martin, Thonhauser, Timo, Welker, Mark E., Jurchescu, Oana D.
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: Nature Publishing Group 2017
Online Access:http://hdl.handle.net/1721.1/107785
Description
Summary:We report on the synthesis and electrical properties of nine new alkylated silane self-assembled monolayers (SAMs) – (EtO)3Si(CH2)nN = CHPhX where n = 3 or 11 and X = 4-CF[subscript 3], 3,5-CF[subscript 3], 3-F-4-CF[subscript 3], 4-F, or 2,3,4,5,6-F, and explore their rectification behavior in relation to their molecular structure. The electrical properties of the films were examined in a metal/insulator/metal configuration, with a highly-doped silicon bottom contact and a eutectic gallium-indium liquid metal (EGaIn) top contact. The junctions exhibit high yields (>90%), a remarkable resistance to bias stress, and current rectification ratios (R) between 20 and 200 depending on the structure, degree of order, and internal dipole of each molecule. We found that the rectification ratio correlates positively with the strength of the molecular dipole moment and it is reduced with increasing molecular length.