title: High-Performance, Solution-Processed, Embedded Multiscale Metallic Transparent Conductors.
abstract: High-performance multiscale metallic transparent conductors (TCs) are demonstrated by incorporating Ag nanowire (NW) networks into microscale Ag grid structures. Highly conductive Ag grids are fabricated via direct imprinting of an Ag ion ink using a reservoir-assisted mold. In this mold, a macroscale cavity, called the "reservoir", is designed to connect to a grid-patterned cavity. The reservoir has a large cavity volume, which reduces unwanted residual layers within the grid spacings by introducing a thinner liquid film. The reservoir undergoes a large volume reduction during mold deformation, which improves ink filling within the grid-patterned cavity through deformation-induced ink injection. The multiscale metallic TCs show a sheet resistance (Rs) of <1.5 Ω/sq and a transmittance (T) of 86% at 550 nm, superior to the corresponding values of Ag NW networks (Rs of 15.6 Ω/sq at a similar T). We estimate the Rs-T performances of the Ag grids using geometrical calculations and demonstrate that their integration can enhance the opto-electrical properties of the Ag NW networks. Multiscale metallic TCs are successfully transferred and embedded into a transparent, flexible, and UV-curable polymer matrix. The embedded multiscale metallic TCs show reasonable electromechanical and chemical stability. The utility of these TCs is demonstrated by fabricating flexible organic solar cells.
authors.affiliation: Department of Mechanical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Yong Suk
authors.initials: YS
authors.lastname: Oh
authors.affiliation: Department of Electrical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Dong Yun
authors.initials: DY
authors.lastname: Choi
authors.affiliation: Department of Mechanical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Sung-Uk
authors.initials: SU
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, POSTECH , 77 Cheongam-ro, Pohang, Kyungbuk 37673, Korea.
authors.forename: Hojin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Electrical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Seunghyup
authors.initials: S
authors.lastname: Yoo
authors.affiliation: Department of Mechanical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Inkyu
authors.initials: I
authors.lastname: Park
authors.affiliation: Department of Mechanical Engineering, KAIST , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Sung
keywords: direct imprinting; embedding; metal grid; silver nanowire; transparent conductor