title: Multi-pulse flash light sintering of bimodal Cu nanoparticle-ink for highly conductive printed Cu electrodes.
abstract: In this work, bimodal Cu nano-inks composed of two different sizes of Cu nanoparticles (NPs) (40 and 100 nm in diameter) were successfully sintered with a multi-pulse flashlight sintering technique. Bimodal Cu nano-inks were fabricated and printed with various mixing ratios and subsequently sintered by a flash light sintering method. The effects of the flashlight sintering conditions, including irradiation energy and pulse number, were investigated to optimize the sintering conditions. A detailed mechanism of the sintering of bimodal Cu nano-ink was also studied via real-time resistance measurement during the sintering process. The sintered Cu nano-ink films were characterized using x-ray photoelectron spectroscopy and scanning electron microscopy. From these results, it was found that the optimal ratio of 40-100 nm NPs was found to be 25:75 wt%, and the optimal multi-pulse flash light sintering condition (irradiation energy: 6 J cm-2, and pulse duration: 1 ms, off-time: 4 ms, and pulse number: 5) was found. The optimally sintered Cu nano-ink film exhibited the lowest resistivity of 5.68 μΩ cm and 5B adhesion level.
authors.affiliation: Department of Mechanical Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul, 133-791, Republic of Korea.
authors.forename: Myeong-Hyeon
authors.initials: MH
authors.lastname: Yu
authors.forename: Sung-Jun
authors.initials: SJ
authors.lastname: Joo
authors.forename: Hak-Sung
authors.initials: HS
authors.lastname: Kim