title: Highly ordered freestanding titanium oxide nanotube arrays using Si-containing block copolymer lithography and atomic layer deposition.
abstract: Highly ordered freestanding TiO(2) nanotube arrays with atomic layer control of wall thickness were fabricated using an organic-inorganic hybrid nanoporous template and atomic layer deposition (ALD). The hybrid nanoporous template with a high-aspect-ratio cylindrical nanopore array can be readily fabricated by pattern transfer from a thin silicon-containing block copolymer film into a thick cross-linked organic polymer layer. The template exhibited excellent thermal stability and thus allowed the high-temperature ALD process to conformally deposit TiO(2) thin films on the inner surface of cylindrical nanopores. The ultrafine thickness tunability of the ALD process made it possible to develop TiO(2) nanotubes with various wall thicknesses. After the template was removed using a dry etch followed by calcination, vertically aligned and highly crystalline anatase TiO(2) nanotube arrays were produced without collapse or bundling. We also fabricated the highly uniform freestanding arrays of multi-component nanotubes composed of TiO(2)/Al(2)O(3)/TiO(2) nanolaminate and Ti-Al-O mixed-phase films with precisely controlled thickness and composition.
authors: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-Gu, Daejeon, Republic of Korea.
authors: Se Jin
authors: SJ
authors: Ku
authors: Gyeong Cheon
authors: GC
authors: Jo
authors: Chang Hong
authors: CH
authors: Bak
authors: Su Min
authors: SM
authors: Kim
authors: Yu Ri
authors: YR
authors: Shin
authors: Kwang Ho
authors: KH
authors: Kim
authors: Se Hun
authors: SH
authors: Kwon
authors: Jin-Baek
authors: JB
authors: Kim