Coherent Resonant Electron Tunneling at 9 and 300 K through a 4.5 nm Long, Rigid, Planar Organic Molecular Wire

Chun Ouyang; Kohei Hashimoto; Hayato Tsuji; Eiichi Nakamura; Yutaka Majima

doi:10.1021/acsomega.8b00559

Coherent Resonant Electron Tunneling at 9 and 300 K through a 4.5 nm Long, Rigid, Planar Organic Molecular Wire

ACS Omega. 2018 May 10;3(5):5125-5130. doi: 10.1021/acsomega.8b00559. eCollection 2018 May 31.

Authors

Chun Ouyang^{1

2}, Kohei Hashimoto³, Hayato Tsuji^{3

4}, Eiichi Nakamura³, Yutaka Majima¹

Affiliations

¹ Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
² Surface and Interface Science Laboratory, RIKEN, Saitama 351-0198, Japan.
³ Department of Chemistry, School of Science, University of Tokyo, Tokyo 113-0033, Japan.
⁴ Department of Chemistry, Faculty of Science, Kanagawa University, Hiratsuka 259-1293, Japan.

Abstract

Organic molecular wires that operate stably at ambient temperatures are a necessary first step toward practical and useful molecular-scale electronic devices, which have thus far been hampered by many factors, including the structural and electron configurational instability of organic molecules. We report here that a single disulfanyl carbon-bridged oligo(phenylenevinylene) (COPV6) molecule embedded between thermally stable electroless Au-plated electrodes of a 4 nm nanogap undergoes coherent resonant tunneling at both 9 and 300 K and functions even after storage in air at room temperature. Such enormous stability is ascribed to the unique structural characteristics of COPV6, that is, rigidity, planarity, thermal stability, resistivity against oxidation and reduction, and an organic insulating sheath that protects the π-system. When sandwiched between the gaps without pinning, this molecule behaves as a Coulomb island with sequential single-electron tunneling at 9 K that disappears at 300 K while maintaining a stable electron flow.