title: Laser-Induced Hydrothermal Growth of Heterogeneous Metal-Oxide Nanowire on Flexible Substrate by Laser Absorption Layer Design.
abstract: Recent development of laser-induced hydrothermal growth enabled direct digital growth of ZnO nanowire array at an arbitrary position even on 3D structures by creating a localized temperature field through a photothermal reaction in liquid environment. However, its spatial size was generally limited by the size of the focused laser spot and the thermal diffusion, and the target material has been limited to ZnO. In this paper, we demonstrated a next generation laser-induced hydrothermal growth method to grow nanowire on a selected area that is even smaller than the laser focus size by designing laser absorption layer. The control of laser-induced temperature field was achieved through adjusting the physical properties of the substrate (dimension and thermal conductivity), and it enabled a successful synthesis of smaller nanowire array without changing any complex optics. Through precise localized temperature control with laser, this approach could be extended to various nanowires including ZnO and TiO2 nanowires even on heat sensitive polymer substrate.
authors.affiliation: †Laser Thermal Lab, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.
authors.forename: Junyeob
authors.initials: J
authors.lastname: Yeo
authors.affiliation: ‡Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Sukjoon
authors.initials: S
authors.lastname: Hong
authors.affiliation: §Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Gunho
authors.initials: G
authors.lastname: Kim
authors.affiliation: ‡Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Habeom
authors.initials: H
authors.lastname: Lee
authors.affiliation: ‡Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Young Duk
authors.initials: YD
authors.lastname: Suh
authors.affiliation: §Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Inkyu
authors.initials: I
authors.lastname: Park
authors.affiliation: †Laser Thermal Lab, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.
authors.forename: Costas P
authors.initials: CP
authors.lastname: Grigoropoulos
authors.affiliation: ‡Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Ko
keywords: flexible substrate; hydrothermal growth; low temperature synthesis; one-step direct growth; selective local laser growth