Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

Frisenda, R.
Perrin, M.L.
Van der Zant, H.S.J.

Applied Sciences

QN/Quantum Nanoscience

2015-12-24

We study single-molecule oligo(phenylene ethynylene)dithiol junctions by means of inelastic electron tunneling spectroscopy (IETS). The molecule is contacted with gold nano-electrodes formed with the mechanically controllable break junction technique. We record the IETS spectrum of the molecule from direct current measurements, both as a function of time and electrode separation. We find that for fixed electrode separation the molecule switches between various configurations, which are characterized by different IETS spectra. Similar variations in the IETS signal are observed during atomic rearrangements upon stretching of the molecular junction. Using quantum chemistry calculations, we identity some of the vibrational modes which constitute a chemical fingerprint of the molecule. In addition, changes can be attributed to rearrangements of the local molecular environment, in particular at the molecule–electrode interface. This study shows the importance of taking into account the interaction with the electrodes when describing inelastic contributions to transport through single-molecule junctions.

current–voltage characteristics
DFT calculations
mechanically controllable break junction (MCBJ)
molecule–electrode interaction
vibrational modes

http://resolver.tudelft.nl/uuid:36c43a64-b032-4395-ba9f-f9c465232bd7

Beilstein-Institut

2190-4286

https://doi.org/10.3762/bjnano.6.257

Beilstein Journal of Nanotechnology, 6, 2015

Institutional Repository

journal article

© 2015 The Author(s)