Fabrication of high-quality copper nanowires flexible transparent conductive electrodes with enhanced mechanical and chemical stability

Abstract

Copper nanowires (Cu NWs) become a potential functional material in future optoelectronic devices owing to their high optical transmittance, super electrical conductivity, and good flexibility as well as low cost. However, the drawbacks of Cu NWs with large contact resistance and poor stability make them far from the practical implementations. Herein we report a robust method to fabricate high-quality Cu NWs transparent conductive electrodes (TCEs) with enhanced mechanical and chemical stability at room temperature. Firstly, we used a sodium borohydride (NaBH4) treatment to remove the organics and oxides on surface of Cu NWs and thus greatly improved the conductivity of Cu NWs TCEs. Subsequently, followed by decorating a dense hydrophobic dodecanethiol (DT) protective layer, the formed Cu NWs TCEs showed superior mechanical and chemical stability compared to the raw ones. The optimized Cu NWs TCEs exhibit a sheet resistance of ∼38 Ω/sq at an optical transmittance of 83% (550 nm). Unlike the bare Cu NWs, the DT-decorated Cu NWs showed good stability under humid conditions at (85% RH) at 85 °C for 12 h. Moreover, the DT-decorated Cu NW TCEs were tested as transparent heaters, showing the fast response time and high saturation temperature under a low DC voltage. Our studies demonstrate that the proper post treatments for Cu NWs TCEs would make them more competitive in application of next-generation electronic and optoelectronic devices.