Electrochemical fabrication of single-crystalline and polycrystalline Au nanowires: the influence of deposition parameters

Abstract

We report the electrochemical growth of gold nanowires with controlled dimensions and crystallinity. By systematically varying the deposition conditions, both polycrystalline and single-crystalline wires with diameters between 20 and 100 nm are successfully synthesized in etched ion-track membranes. The nanowires are characterized using scanning electron microscopy, high resolution transmission electron microscopy, scanning tunnelling microscopy and x-ray diffraction. The influence of the deposition parameters, especially those of the electrolyte, on the nanowire structure is investigated. Gold sulfite electrolytes lead to polycrystalline structure at the temperatures and voltages employed. In contrast, gold cyanide solution favours the growth of single crystals at temperatures between 50 and 65 °C under both direct current and reverse pulse current deposition conditions. The single-crystalline wires possess a [110] preferred orientation.

Efficient field emission from structured gold nanowire cathodes

“…This conductive backing layer with improved mechanical stability served as a substrate of the cathode. The deposition of Au into the pores was performed in a galvanic cell using a potassium dicyanoaurate (I) solution (Puramet 402, Doduco GmbH) with 10 g/l of gold at 50 o C and a gold rod as anode [8] The morphology of typical Au-NW structures before and after the FE measurements was investigated by SEM (Phillips XL30 at GSI and Phillips XL30S at Univ. Wuppertal).…”

“…Metal nanowires (NW) with high aspect ratio (AR) and high conductivity fabricated by the ion-track template technique [6,7] provide an interesting alternative. The method allows in particular the control of the number density of NW by the fluence applied during template irradiation, whereas the wire diameter and length are controlled by time of the track etching and electrochemical deposition, respectively [8].…”

Formation of atomic‐sized contacts controlled by electrochemical methods

“…In this work we report results obtained with aqueous KCN and NaCl solutions. Cyanide is reported to lead to single-crystalline deposition of nanowires with the appropriate parameters [27]. This would be important in the case where single-crystallinity is relevant, but in the work reported here it is not critical whether the contact is polycrystalline or a single-crystal.…”

Optical and electrical properties of gold nanowires synthesized by electrochemical deposition

“…[13][14][15] The ease and low cost of the process means it is very attractive option for industrial applications. Preparing nanowires in the etched ion-track template with electrodeposition has the advantage that the nanowires can be grown with large aspect ratios and vertical alignment on a substrate.…”

“…Furthermore, the density of the nanowire in the template can be adjusted easily by varying the fluence of the irradiating ions. We have previously reported the gold, 15 copper, 11 cobalt, 16 CdS, 10 and polypyrrole nanowires 17 deposited into ion-track templates.…”