Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices

Details Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices

2005-02-17

arxiv.org/abs/cond-mat/0502432v1

Physics

Condensed Matter

Materials Science

38 p 8 Fig

Scientific paper

10.1063/1.2005372

We have fabricated a variety of novel molecular diodes based on self-assembled-monolayers (SAM) of solid-state mixture of molecular wires (1,4 benzene-dimethane-thiol), and molecular insulator spacers (1-pentanethiol) with different concentration ratios r of wires/spacers, which were sandwiched between two gold (Au) electrodes. We introduce two new methods borrowed from Surface Science to (i) confirm the connectivity between the benzene-dimethane-thiol molecules with the upper Au electrode, and (ii) count the number of isolated molecular wires in the devices. The electrical transport properties of the SAM diodes were studied at different temperatures via the conductance and differential conductance spectra. We found that a potential barrier caused by the spatial connectivity gap between the pentanethiol molecules and the upper Au electrode dominates the transport properties of the pure pentanethiol SAM diode (r = 0). The transport properties of molecular diodes with low r-values are dominated by the conductance of the isolated benzene-dimethane-thiol molecules in the device. We found that the temperature dependence of the molecular diodes is much weaker than that of the pure pentanethiol device indicating the importance of the benzene-dimethane-thiol simultaneous bonding to the two Au electrodes that facilitate electrical transport. From the differential conductance spectra we also found that the energy difference, Delta between the Au electrode Fermi-level and the benzene-dimethane-thiol HOMO (or LUMO) level is ~1.5 eV; whereas it is ~2.5 eV for the pentanethiol molecule. The weak temperature dependent transport that we obtained for the SSM diodes reflects the weak temperature dependence of Delta.

Affiliated with

Also associated with

No associations

Rating

Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transport Studies of Isolated Molecular Wires in Self-Assembled Monolayer Devices will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-387646