title: Graphoepitaxy of block-copolymer self-assembly integrated with single-step ZnO nanoimprinting.
abstract: A highly efficient, ultralarge-area nanolithography that integrates block-copolymer lithography with single-step ZnO nanoimprinting is introduced. The UV-assisted imprinting of a photosensitive sol-gel precursor creates large-area ZnO topographic patterns with various pattern shapes in a single-step process. This straightforward approach provides a smooth line edge and high thermal stability of the imprinted ZnO pattern; these properties are greatly advantageous for further graphoepitaxial block-copolymer assembly. According to the ZnO pattern shape and depth, the orientation and lateral ordering of self-assembled cylindrical nanodomains in block-copolymer thin films could be directed in a variety of ways. Significantly, the subtle tunability of ZnO trench depth enabled by nanoimprinting, generated complex hierarchical nanopatterns, where surface-parallel and surface-perpendicular nanocylinder arrays are alternately arranged. The stability of this complex morphology is confirmed by self-consistent field theory (SCFT) calculations. The highly ordered graphoepitaxial nanoscale assembly achieved on transparent semiconducting ZnO substrates offers enormous potential for photonics and optoelectronics.
authors.affiliation: Nanomechanical System Research Center, Korea Institute of Machinery and Materials, Daejeon, Republic of Korea.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kim
authors.forename: Dong Ok
authors.initials: DO
authors.lastname: Shin
authors.forename: Dae-Geun
authors.initials: DG
authors.lastname: Choi
authors.forename: Jong-Ryul
authors.initials: JR
authors.lastname: Jeong
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Mun
authors.forename: Yong-Biao
authors.initials: YB
authors.lastname: Yang
authors.forename: Jaeup U
authors.initials: JU
authors.lastname: Kim
authors.forename: Sang Ouk
authors.initials: SO
authors.lastname: Kim
authors.forename: Jun-Ho
authors.initials: JH
authors.lastname: Jeong