Temperature-dependent and bistable current-voltage measurements in zinc porphyrin molecular junctions.
We report bistability in current-voltage curves from di(PEP)PorZn in an electromigrated molecular junction. Bistability was observed at ±0.3 V at 300 K but did not occur at 4 K. No bistability was identified at 300 K for another porphyrin molecule (di(Xyl)PorZn), where the phenyl-ethnyl-phenyl (PEP) side groups were replaced with a flexible p-xylene. Molecular dynamics simulations show that bistability may be due to conformation changes related to the fluctuation of the dihedral angle surrounding the zinc and/or the rotation of the porphyrin central plane of the molecule. Results suggest that other mechanisms may play a role in the current-voltage characteristics observed.
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Swatilekha
S
Saha
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Adrien
A
Nicolaï
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Jonathan R
JR
Owens
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Alexandra
A
Krawicz
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Peter H
PH
Dinolfo
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Vincent
V
Meunier
†Department of Physics, Applied Physics, and Astronomy, ‡Department of Chemistry and Chemical Biology, and §Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Kim M
KM
Lewis
bistability; electromigration; molecular dynamic simulations; molecular junctions; porphyrin; temperature dependence