Electrical Conductance of Oligothiophene Molecular Wires

• Published in: Nano letters Vol. 8; no. 4; pp. 1237 - 1240
• Main Authors: Yamada, Ryo, Kumazawa, Hiroaki, Noutoshi, Tomoharu, Tanaka, Shoji, Tada, Hirokazu
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.04.2008
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Physics; Quantum wires; Electrical measurement; Scanning tunneling microscopy; Thiophene derivative polymer; Molecular wires; Size effect; Tunnel effect; Thiocyanates; Electrical conductance
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl0732023

A break junction method using a scanning tunneling microscope has been applied to electrical conductance measurement of newly designed oligothiophene molecules terminated with a thiocyanate group. The tunneling conduction was evident from an exponential decay of the conductance as a function of the molecular length up to ca. 6 nm. The tunneling decay constant was estimated to be 0.1 Å−1. The pre-exponential factor was 1.3 × 10−6 S, which was smaller than that observed for alkanedithiols.