Tuning the thickness of electrochemically grafted layers in large area molecular junctions

Journal Article · Sun Sep 21 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4896106· OSTI ID:22306229

Fluteau, T.; Bessis, C.; Della Rocca, M. L.; Lafarge, P. ^[1]; Martin, P.; Lacroix, J. -C. ^[2]

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1. Université Paris Diderot, Sorbonne Paris Cité, MPQ, UMR 7162, CNRS, 75205 Paris Cedex 13 (France)
2. Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, 15 rue J.-A. de Baïf, 75205 Paris Cedex 13 (France)

We have investigated the thickness, the surface roughness, and the transport properties of oligo(1-(2-bisthienyl)benzene) (BTB) thin films grafted on evaporated Au electrodes, thanks to a diazonium-based electro-reduction process. The thickness of the organic film is tuned by varying the number of electrochemical cycles during the growth process. Atomic force microscopy measurements reveal the evolution of the thickness in the range of 2–27 nm. Its variation displays a linear dependence with the number of cycles followed by a saturation attributed to the insulating behavior of the organic films. Both ultrathin (2 nm) and thin (12 and 27 nm) large area BTB-based junctions have then been fabricated using standard CMOS processes and finally electrically characterized. The electronic responses are fully consistent with a tunneling barrier in case of ultrathin BTB film whereas a pronounced rectifying behavior is reported for thicker molecular films.

• OSTI ID: 22306229
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC FORCE MICROSCOPY
CRYSTAL GROWTH
ELECTRIC CONDUCTIVITY
ELECTRIC CONTACTS
ELECTROCHEMISTRY
ELECTRODES
GOLD
LAYERS
MOLECULES
ORGANIC SEMICONDUCTORS
ROUGHNESS
SATURATION
SEMICONDUCTOR JUNCTIONS
SURFACES
THICKNESS
THIN FILMS
TUNNEL EFFECT