Synthesis of copper nanowires and facile fabrication of nanostructured conductors with high transparency in 400–2500 nm spectral range

Abstract

We studied the effect of parameters of a hydrothermal synthesis of copper nanowires on their dimensional characteristics. A robust protocol for the synthesis and isolation of copper nanowires with an average diameter of about 60 nm and a length of about 90 μm was developed. The final dispersion enriched with target nanowires purified from low-volatile oleylamine involved in the synthesis was used to fabricate transparent conductive films by spin coating. To increase the conductivity of the films, the rapid and efficient technique of removing the native oxide shell of nanowires utilizing the solution of formic acid in isopropyl alcohol was proposed. The fabricated transparent conductors have record-breaking characteristics: light transmittance of about 93 % (at a wavelength of 550 nm) with the sheet resistance of about 34 Ohm/sq. An important point is that the transmittance of the films with sheet resistance down to 30 Ohm/sq. exceeds 90 % in the wide spectral range (400–2500 nm), thus opening up great opportunities for applications of such nanomaterials in optoelectronics.