Enhancement of the Conductivity and Uniformity of Silver Nanowire Flexible Transparent Conductive Films by Femtosecond Laser-Induced Nanowelding

In order to improve the performance of silver nanowire (AgNW) flexible transparent conductive films (FTCFs), including the conductivity, uniformity, and reliability, the welding of high repetition rate femtosecond (fs) laser is applied in this work. Fs laser irradiation can produce local enhancement of electric field, which induce melting at the gap of the AgNWs and enhance electrical conductivity of nanowire networks. The overall resistivity of the laser-welded AgNW FTCFs reduced significantly and the transparency changed slightly. Meanwhile, PET substrates were not damaged during the laser welding procedure in particular parameters. The AgNW FTCFs can achieve a nonuniformity factor of the sheet resistance as 4.6% at an average sheet resistance of 16.1 Ω/sq and transmittance of 91%. The laser-welded AgNW FTCFs also exhibited excellent reliability against mechanical bending over 10,000 cycles. The welding process may open up a new approach for improvement of FTCFs photoelectric property and can be applied in the fabrication of silver nanostructures for flexible optoelectronic and integration of functional devices.