Engineering Nonlinear Electrical Behavior with Asymmetric Multisegmented Polymer–Metal Nanowires

In this paper, we report on novel hybrid nanowires as prototypical building blocks for nanocomponents. Multisegmented hybrid nanowires (HNWs) made of metallic and conjugated polymer (CP) segments were elaborated and the impact of metal/polymer interfaces on the rectifying behavior was determined. Using HNWs integrated into micromachined devices, the relationship between electronic properties and original structure is revealed. By combining transmission electron microscopy (TEM) directly on the symmetric and asymmetric HNWs structures studied by current–voltage (I–V) spectroscopy, we show that rectifying I–V characteristics are observed only for asymmetric HNWs. Moreover, it is shown that the rectification ratio can be improved up to 3 orders of magnitude by a proper selection of the HNW composition. While the rectifying behavior is observed in HNWs after oxidative or acid doping, the charge transport mechanism in as-synthesized HNWs is bulk-limited and independent from their structure. Both symmetric and asymmetric HNWs exhibit Ohmic and nonlinear I–V curves above and below TNL ≈ 120 K, respectively. These electrical behaviors are consistent with a progressive transition from an Ohmic to a non-Ohmic variable-range-hopping (VRH) mechanism. We discuss the origin of these nonlinearities, comparing the two- and four-probe measurements on single HNWs, and we propose a simple model based on dual back-to-back Schottky diodes to explain qualitatively the rectifying properties.