Electrochemically Template-Grown Multi-Segmented Gold-Conducting Polymer Nanowires with Tunable Electronic Behavior

Abstract

Multisegmented nanowires (NWs) based on poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) are synthesized by an all-electrochemical template method for precise control over segment dimensions. We study the influence of different parameters on the growing process of the PEDOT segment and on the mechanical strength of the conjugated polymer/metal interfaces in tri-segmented Au-PEDOT-Au and tetra-segmented Au-PEDOT-PPy-Au NWs. The coexistence of PEDOT and PPy in tetra-segmented NWs is confirmed by high resolution transmission electron microscopy coupled with energy-dispersive X-ray analysis. We investigate the electrical transport of individual multisegmented NWs of both types at room temperature. An interesting feature of the tetra-segmented NWs compared to tri-segmented NWs is the switching of their electrical characteristics in function of the redox state of the two conjugated polymer blocks.

Conjugated Polymer and Hybrid Polymer-Metal Single Nanowires: Correlated Characterization and Device Integration

“…the blue curve corresponds to the as-synthesized NW, the red curve has been obtained after FeCl 3 treatment. The observed increase of electrical conductivity of the PEDOT segment could be understood by a shift in the dopant anion equilibrium within the PEDOT [Callegari (2009)]. The chloride ions inserted during the chemical treatment effectively adjust the low dimensional carrier hopping network on the backbone of the polymer inducing an enhanced charge transport.…”

Using the Hard Templating Method for the Synthesis of Metal‐Conducting Polymer Multi‐Segmented Nanowires

“…Moreover, the robustness of the upper metal-ontopolymer interface can be optimized by adjusting the electropolymerization conditions. In particular, we recently showed [78] that the potential scan rate has a huge impact on the shape and consequently, on the mechanical strength of the interface. For each investigated pore diameter of the template, an optimal value of the potential scan rate was found, at which a rather long metal meniscus ensures a strong mechanical link between the two materials.…”

“…(a) Upper metal-onto-polymer interface morphology dependence on the potential scan rate. [78] (b) Bottom polymer-onto-metal interface improvement using a strategy based on SAMs. Figure 5.…”

“…By using platinum for the metallic segments in M/PPy systems, more elaborated structures presenting several PPy junctions and consequently, many metal/polymer interfaces were successfully prepared (Figure 7c and d). We also fabricated tetra-segmented nanowires presenting a polymer heterojunction (PEDOT-PPy) [78] (Figure 7e). For this system, the sequence of polymer deposition was determined according to previous observations on the shape and strength of the different metal/polymer interfaces.…”

A Review on Electronic Transport Properties of Individual Conducting Polymer Nanotubes and Nanowires

“…In this two-probe geometry, the contact resistance can be minimized by applying a significant pressure of the tip onto the nanotube/wire. A common approach was generally realized by dispersing nanotubes/wires on patterned micro-or nanoelectrodes prepared by photo-lithography, electron-beam lithography and focused-ion beam deposition, followed by the subsequent searching of nanofibers just lying on the two or four electrodes only (Kim et al, 1999;MacDiarmid et al, 2001;Park et al, 2003;Lee et al, 2004;Aleshin et al, 2004;Samitsu et al, 2005;Joo et al, 2005;Aleshin, 2006;Gence et al, 2007Gence et al, & 2008Callegari et al, 2009). Particularly, focused-ion beam assisted deposition technique has been employed to attach metal microleads on isolated www.intechopen.com A Review on Electronic Transport Properties of Individual Conducting Polymer Nanotubes and Nanowires 225 nanotubes/wires directly (Long et al, 2003a(Long et al, , 2004b(Long et al, & 2005bHuang et al, 2006;Long et al, 2006c;Duvail et al, 2007;Lu et al, 2007;Long et al, 2008aLong et al, & 2009b.…”