title: A highly reliable copper nanowire/nanoparticle ink pattern with high conductivity on flexible substrate prepared via a flash light-sintering technique.
abstract: In this work, copper nanowires (NWs) and Cu nanoparticles (NPs) were employed to increase the reliability of a printed electrode pattern under mechanical bending fatigue. The fabricated Cu NW/NP inks with different weight fractions of Cu NWs were printed on a polyimide substrate and flash light-sintered within a few milliseconds at room temperature under ambient conditions. Then, 1000 cycles of outer and inner bending fatigue tests were performed using a lab-made fatigue tester. The flash light-sintered Cu NW/NP ink film with 5 wt % Cu NWs prepared under the flash light-sintering conditions (12.5 J·cm–2 irradiation energy, 10 ms pulse duration, and one pulse) showed a lower resistivity (22.77 μΩ·cm) than those of the only Cu NPs and Cu NWs ink (94.01 μΩ·cm and 104.15 μΩ·cm, respectively). In addition, the resistance change (ΔR·R0(–1)) of the 5 wt % Cu NWs Cu NW/NP film was greatly enhanced to 4.19 compared to the 92.75 of the Cu NPs film obtained under mechanical fatigue conditions over 1000 cycles and an outer bending radius of 7 mm. These results were obtained by the densification and enhanced mechanical flexibility of flash light-sintered Cu NW/NP network, which resulted in prevention of crack initiation and propagation. To characterize the Cu NW/NP ink film, X-ray diffraction and scanning electron microscopy were used.
authors.affiliation: §Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea.
authors.forename: Sung-Jun
authors.initials: SJ
authors.lastname: Joo
authors.affiliation: §Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea.
authors.forename: Sung-Hyeon
authors.initials: SH
authors.lastname: Park
authors.affiliation: §Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea.
authors.forename: Chang-Jin
authors.initials: CJ
authors.lastname: Moon
authors.affiliation: §Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea.|‡Institute of Nano Science and Technology, Hanyang University, Seoul, 133-791, Korea.
authors.forename: Hak-Sung
authors.initials: HS
authors.lastname: Kim
keywords: copper nanoparticles; copper nanowires; flash light sintering; printed electronics; reliability of electrode