We present an investigation of electrical transport through fused and orthogonal dithiolated porphyrin arrays of different molecular lengths. Length dependence measurements show that conductance decreases much more slowly with molecular length than the exponential dependence expected for a coherent tunneling process. It suggests that the electrical conduction through porphyrin arrays is mainly due to the thermally activated hopping transport. From the temperature dependence of ISD-VSD curves, the thermal activation energy Ea is estimated to be about 0.35 eV at zero-bias voltage, independently of molecular conformation and length.
Bibliographical noteFunding Information:
This work has been financially supported by the Korea Science and Engineering Foundation (KOSEF) through National Core Research Center for Nanomedical Technology (K.H.Y.) and the National Creative Research Initiatives Program of KOSEF (D.K.). The work at Kyoto was supported by the Core Research for Evolutional Science and Technology of Japan Science and Technology Corporation (CREST).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry