Redox-induced asymmetric electrical characteristics of ferrocene- alkanethiolate molecular devices on rigid and flexible substrates

The electrical properties of ferrocene-alkanethiolate self-assembled monolayers (SAMs) on a high yield solid-state device structure are investigated. The devices are fabricated using a conductive polymer interlayer between the top electrode and the SAM on both silicon-based rigid substrates and plastic-based flexible substrates. Asymmetric electrical transport characteristics that originate from the ferrocene moieties are observed. In particular, a distinctive temperature dependence of the current (i.e., a decrease in current density as temperature increases) at a large reverse bias, which is associated with the redox reaction of ferrocene groups in the molecular junction, is found. It is further demonstrated that the molecular devices can function on flexible substrates under various mechanical stress configurations with consistent electrical characteristics. This study enhances the understanding of asymmetric molecules and may lead to the development of functional molecular electronic devices on both rigid and flexible substrates. The electrical properties of ferrocene-alkanethiolate molecular devices on both rigid and flexible substrates are studied. A distinctive temperature dependence of the current (i.e., a decrease in current as temperature increases) upon an applied bias polarity, which is associated with the redox of ferrocene groups in the junctions, is observed. The flexible molecular devices function consistently under various mechanical stress configurations.