title: Controlling Smectic Liquid Crystal Defect Patterns by Physical Stamping-Assisted Domain Separation and Their Use as Templates for Quantum Dot Cluster Arrays.
abstract: Controlling the organization of self-assembling building blocks over a large area is crucial for lithographic tools based on the bottom-up approach. However, the fabrication of liquid crystal (LC) defect patterns with a particular ordering still remains a challenge because of the limited close-packed morphologies of LC defects. Here, we introduce a multiple-stamping domain separation method for the control of the dimensions and organization of LC defect structures. Prepatterns with various grid shapes on planar polyimide (PI) surfaces were fabricated by pressing a line-shaped stamp into the PI surfaces in two different directions, and then these surfaces were used to prepare LC defect structures confined to these grid domains. The dimensions of the LC defect structures, namely, the equilibrium diameter and the center to center spacing, are controlled by varying the line spacing of the stamps and the film thickness. A variety of arrangements of LC defects, including square, rhombic, hexagonal, and other oblique lattices, can be obtained by simply varying the stamping angle (Ω) between the first and second stamping directions. Furthermore, we demonstrate that the resulting controllable LC defect arrays can be used as templates for generating various patterns of nanoparticle clusters by trapping quantum dots (QDs) within the cores of the LC defects.
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Ok
authors.affiliation: Advanced Functional Materials Group, Korea Research Institute of Chemical Technology , Daejeon 34114, Korea.
authors.forename: Yun Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Lee
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Hae-Wook
authors.initials: HW
authors.lastname: Yoo
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Kiok
authors.initials: K
authors.lastname: Kwon
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Woo-Bin
authors.initials: WB
authors.lastname: Jung
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Shin-Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: KAIST Institute for Nanocentury (KINC) and Department of Chemical and Biomolecular Engineering (BK-21 Plus), Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
authors.forename: Hee-Tae
authors.identifier: 0000-0002-5727-6732
authors.initials: HT
authors.lastname: Jung