title: A solid-state cation exchange reaction to form multiple metal oxide heterostructure nanowires.
abstract: Metal oxide nanostructures have been investigated extensively due to their wide range of physical properties; zinc oxide is one of the most promising materials. It exhibits fascinating functional properties and various types of morphologies. In particular, ZnO heterostructures have attracted great attention because their performance can be modified and further improved by the addition of other materials. In this study, we successfully transformed ZnO nanowires (NWs) into multiple ZnO/Al2O3heterostructure NWs via a solid-state cation exchange reaction. The experiment was carried out in situ via an ultrahigh vacuum transmission electron microscope (UHV-TEM), which was equipped with a video recorder. Moreover, we analyzed the structure and composition of the heterostructure NWs by Cs-corrected STEM equipped with EDS. Based on these experimental results, we inferred a cation exchange reaction ion path model. Additionally, we investigated the defects that appeared after the cation reaction, which resulted from the remaining zinc ions. These multiple heterostructure ZnO/Al2O3NWs exhibited excellent UV sensing sensitivity and efficiency.
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: Y H
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: C W
authors.initials: CW
authors.lastname: Huang
authors.affiliation: Department of Physics, Tam Kang University, New Taipei 251, Taiwan.
authors.forename: P H
authors.initials: PH
authors.lastname: Yeh
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: J Y
authors.initials: JY
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: T Y
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: C F
authors.initials: CF
authors.lastname: Chang
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
authors.forename: W W
authors.initials: WW
authors.lastname: Wu