Novel facile synthesis and room-temperature sintering of copper nanowires for solution-processed transparent conductive films

Abstract

Copper nanowires (Cu NWs) are considered as the potential alternative material for indium tin oxide (ITO) which is widely used in various photoelectric devices. However, the effective and full solution-processed technology for Cu NWs transparent conductive films (TCFs) with excellent performance is lacking. Here, a facile “heterogeneous-self reduction” approach was proposed for Cu NWs synthesis with the yield as high as 62.2% using nether reductant nor crystal seed. Copper glycine heated with hexadecyltrimethylammonium chloride and oleylamine, decomposed continuously to release Cu atoms, which were nucleated and grown anisotropically into Cu NWs with aspect ratio > 1000. The “pickling-chemical sintering” solution-process was applied to form the Cu NWs TCFs using the synthesized Cu NWs. Oleylamine on the surface of purified Cu NWs was removed by pickling with acetic acid solution. After coating on PET film, the surface oxide of Cu NWs could be reduced to Cu (0) by NaBH4 solution, and the sintering of Cu NWs can be realized simultaneously. The Cu NWs TCF with a sheet resistance of 34.7 Ω sq–1 at a transmittance of 91.1% exhibits the excellent performance in capacitive sensing. This work is expected to promote the full-solution preparing of Cu NWs TCFs.