Solution-processed Cu@Au nanowires for transparent conductive films and electromagnetic shielding

Abstract

Cu nanowires (NWs) have become a research hotspot in the field of metal NWs because of their excellent electrical conductivity, optoelectronic properties, mechanical properties and low price. However, the instability of Cu NWs leads to the loss of conductivity, which largely limits their application in optoelectronic functional devices. Here, we propose an aqueous-phase synthesis method for the direct synthesis of Cu@Au composite NWs. Cu@Au NWs/poly(ethylene terephthalate) (PET) flexible transparent conductive films (FTCFs) were prepared through vacuum filtration of Cu@Au NWs. The stability tests of Cu@Au NWs/PET FTCFs showed that the resistance of the Cu@Au NWs/PET films remained stable for 60 days, which was much better than that of the Cu NWs/PET FTCFs. The conductivity and transmittance of the Cu@Au NWs/PET FTCFs remained highly stable after 10 000 bending cycles. To expand the applicability of Cu@Au NWs/PET films in electromagnetic shielding, the softer Cu@Au NWs/poly(L-lactic acid) (PLLA) FTCFs were prepared via a spin-coating process, and the film with a square resistance of 5 Ω sq⁻¹ displayed excellent electromagnetic shielding performance, with an electromagnetic shielding efficiency value of up to 32 dB in the X-band.