Abstract
The energy level alignment change in single-molecule junctions during junction elongation was investigated by using multi-IV measurements with a scanning tunneling micro-scope break-junction technique. We used 1,2-bis(4-pyridyl)ethylene molecule with Au electrodes, and observed a negative slope in the conductance trace during junction elongation. The trace was divided into three regions having high, middle, and low conductance in that order with increasing elongation. The values of the conductance and the thermopower obtained by multi-IV measurements with a temperature gradient were used to determine the energy level alignment changes of the molecule during junction elongation in each region, where the dominant orbital for transport is the lowest unoccupied molecular orbital. We found that the energy level alignment gets closer to the Au Fermi energy with decreasing conductance. These results thus provide quantitative information on energy level alignments in a metal-molecule interface during junction elongation and evolution.
Similar content being viewed by others
References
J. A. Malen, P. Doak, K. Baheti, T. D. Tilley, R. A. Segalman and A. Majumdar, Nano Lett. 9, 1164 (2009).
J. M. Beebe, V. B. Engelkes, L. L. Miller and C. D. Frisbie, J. Am. Chem. Soc. 124, 11268 (2002).
M. Dell’Angela et al., L. Nano Lett. 10, 2470 (2010).
C. D. Zangmeister et al., J. Phys. Chem. B 110, 17138 (2006).
B. Xu, X. Xiao and N. J. Tao, J. Am. Chem. Soc. 125, 16164 (2003).
B. Xu and N. J. Tao, Science 301, 1221 (2003).
M. L. Perrin et al., Nat. Nano 8, 282 (2013).
G. Heimel, L. Romaner, E. Zojer and J. L. Brédas, Nano Lett. 7, 932 (2007).
G. Heimel, L. Romaner, J. L. Brédas and E. Zojer, Phys. Rev. Lett. 96, 196806 (2006).
D. Cahen and A. Kahn, Adv. Mater. 15, 271 (2003).
B. Kim, S. H. Choi, X. Y. Zhu and C. D. Frisbie, J. Am. Chem. Soc. 133, 19864 (2011).
J. R. Widawsky, P. Darancet, J. B. Neaton and L. Venkataraman, Nano Lett. 12, 354 (2012).
Y. S. Park et al., J. Am. Chem. Soc. 129, 15768 (2007).
L. Venkataraman, J. E. Klare, I. W. Tam, C. Nuckolls, M. S. Hybertsen and M. L. Steigerwald, Nano Lett. 6, 458 (2006).
T. J. Kim, Phys. Chem. C 119, 12703 (2015).
P. S. Yoo, H. Y. Jo and T. J. Kim, Phys. Chem. C 118, 29962 (2014).
S. K. Yee, J. A. Malen, A. Majumdar and R. A. Segalman, Nano Lett. 11, 4089 (2011).
P. Reddy, S. Y. Jang, R. A. Segalman and A. Majumdar, Science 315, 1568 (2007).
T. Kim, P. Darancet, J. R. Widawsky, M. Kotiuga, S. Y. Quek, J. B. Neaton and L. Venkataraman, Nano Lett. 14, 794 (2014).
S. V. Aradhya, M. Frei, M. S. Hybertsen and L. Venkataraman, Nat Mater 11, 872 (2012).
M. Frei, S. V. Aradhya, M. Koentopp, M. S. Hybertsen and L. Venkataraman, Nano Lett. 11, (2011) 1518.
M. Kamenetska et al., J. Am. Chem. Soc. 132, 6817 (2010).
S. Y. Quek et al., Nat Nano 4, 230 (2009).
M. Paulsson and S. Datta, Phys. Rev. B 67, 241403 (2003).
R. Frisenda, M. L. Perrin, H. Valkenier, J. C. Hummelen and H. S. van der Zant, Physica Status Solidi (b) 250, 2431 (2013).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Park, J.W., Kim, T. Variation of energy level alignment in molecular junction elongation. Journal of the Korean Physical Society 69, 1673–1676 (2016). https://doi.org/10.3938/jkps.69.1673
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3938/jkps.69.1673