Highly electrically stable Ag-Au core-shell nanowires-based transparent conductive films

Silver nanowires (AgNWs)-based transparent conductive films (TCFs) have emerged as highly promising alternatives to indium tin oxide (ITO) for flexible optoelectronic devices, but still face the challenge of electrical stability of AgNWs. Herein, highly electrically stable Ag-Au core-shell nanowires-based TCFs (Au@AgNWs TCFs) were fabricated by slot-die coating. Gold is uniformly grown on the surface of AgNWs by in situ reduction to construct Ag-Au core-shell structure with a gold shell thickness of 10 nm. The resultant Au@AgNWs TCF has superior optoelectronic properties with a transmittance of 92 % at 550 nm and a sheet resistance of 45 Ω/sq. Compared to the uncoated AgNWs TCF, the Au@AgNWs TCF shows slightly reduced optoelectronic performance, but exhibits significantly enhanced electrical stability. Under continuous operation at 12 V, the resistance of Au@AgNWs TCF only increases by 1.4 times after 18 h, whereas the uncoated AgNWs TCF fails after just 30 min. DFT calculations on the Ag (100)/Au (111) interface confirm the structural stability with a strong adhesion of 1.49 J m −2 and a low interfacial energy of 0.047 J m −2 . Differential charge density and DOS reveal significant charge transfer and the formation of an interfacial dipole field to strengthen interfacial bonding and suppress electromigration. CI-NEB calculations show that the Au layer significantly increases the migration barriers for Ag atoms, suppressing migration and enhancing the stability of the interface.