title: Self-Etching-Induced Morphological Evolution of ZnO Microrods Grown on FTO Glass by Hydrothermal Method.
abstract: In this research, the zinc oxide (ZnO) microrods were grown by hydrothermal method on fluorine-doped tin oxide (FTO) glass functionalized by self-assembled monolayer of octadecyltrimethoxysilane (ODS; CH3(CH2)17Si(OCH3)3). The sharp-tip or polygonal shape with specific facets at the top end of ZnO microrods can be obtained by post retention at low temperature. The morphologies were characterized by the field-emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM). The results confirm that the morphology change at the top end is due to self-etching. The mechanism responsible for the formation of various top-end morphologies was proposed. The specific facets that left after 6-h retention were identified. The room-temperature micro-photoluminescence spectra showed a strong ultraviolet emission at 387 nm, and a broad emission at a range of from 500 to 700 nm. The morphology change also influences the photoluminescence (PL) spectra. A satellite peak in the UV emission spectra was observed. The peak may be attributed to the morphology effect of the microrods.
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan. wendung@mail.ncku.edu.tw.
authors.forename: Wen-Dung
authors.initials: WD
authors.lastname: Hsu
authors.affiliation: Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan. tsaijk@nfu.edu.tw.
authors.forename: Jenn-Kai
authors.initials: JK
authors.lastname: Tsai
authors.affiliation: Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan. thmeen@nfu.edu.tw.
authors.forename: Teen-Hang
authors.initials: TH
authors.lastname: Meen
authors.affiliation: Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan. eetcwu@nfu.edu.tw.
authors.forename: Tian-Chiuan
authors.initials: TC
authors.lastname: Wu
authors.affiliation: Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan. d2334381@yahoo.com.tw.
authors.forename: Yan-Kuan
authors.initials: YK
authors.lastname: He
authors.affiliation: Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan. 49839055@stust.edu.tw.
authors.forename: Yu-Da
authors.initials: YD
authors.lastname: Lai
keywords: HMT; Hydrothermal method; Micropencil; Microrod; ODS; Zn(NO3)2·6H2O; ZnO