Electrochemical Fabrication of (TMTSF)₂ X (X = PF₆, BF₄, ClO₄) Nanowires

TMTSF-based (TMTSF = tetramethyltetraselenafulvalene = C₁₀H₁₂Se₄) charge-transfer salt nanowires were fabricated using the galvanostatic deposition technique that was assisted by an anodic aluminum oxide (AAO) template. By applying a low current density of 1–2 μA/cm² for more than one month, nanowire arrays with diameters of ∼150 nm and lengths of ∼6 μm were obtained. The length of nanowires can be controlled by the duration of the constant current application. Energydispersive X-ray spectroscopic (EDX) analysis confirmed that selenium is one of the main components of the nanowires. The micro-Raman (v ₃C=C) and FT-IR spectra (v ₃PF₆ ^–, v ₃BF₄ ^–, v ₃ClO₄ ^–) indicated that the nanowire arrays had the (TMTSF)₂ X (X = PF₆, BF₄, ClO₄) phase. The TEM images and the selected area electron diffraction (SAED) patterns indicate that the nanowires were not single crystals, but the current–voltage characteristic that was measured with the four-terminal method showed the conductivity of the (TMTSF)₂PF₆ single crystals (σ_RT = 1.6 S/cm) at room temperature.