title: Growth of dumbbell-like ZnO microcrystals under mild conditions and their photoluminescence properties.
abstract: Large-scale uniform dumbbell-like ZnO microcrystals were successfully synthesized via a facile solution method under mild conditions. The as-prepared dumbbells, with lengths of 3.5-5.4 microm and diameters of 1.3-1.8 microm, possess a single-crystal hexagonal structure and grow along the [0001] direction. The influence of the reactant concentration on the size and shapes of the ZnO samples had been studied, and the results revealed that the reactant concentration plays a crucial role in determining final morphologies of the samples. Moreover, the evolution process of the dumbbell-like ZnO microcrystals was viewed by field-emission scanning electron microscopy (FE-SEM) characterization, and a possible formation mechanism was proposed. In addition, optical properties of the ZnO samples prepared at different reaction times were also investigated by photoluminescence (PL) spectroscopy. The room-temperature PL spectrum of the dumbbell-like ZnO microcrystals shows a strong UV emission peak. The UV emission is further identified to originate from the radiative free-exciton recombination by the temperature-dependent PL.
authors.affiliation: National Laboratory of Superhard Materials, Jilin University, Changchun, 130012, P. R. China.
authors.forename: Qingjiang
authors.initials: Q
authors.lastname: Yu
authors.forename: Cuiling
authors.initials: C
authors.lastname: Yu
authors.forename: Haibin
authors.initials: H
authors.lastname: Yang
authors.forename: Wuyou
authors.initials: W
authors.lastname: Fu
authors.forename: Lianxia
authors.initials: L
authors.lastname: Chang
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Ronghui
authors.initials: R
authors.lastname: Wei
authors.forename: Hongdong
authors.initials: H
authors.lastname: Li
authors.forename: Hongyang
authors.initials: H
authors.lastname: Zhu
authors.forename: Minghui
authors.initials: M
authors.lastname: Li
authors.forename: Guangtian
authors.initials: G
authors.lastname: Zou
authors.forename: Guorui
authors.initials: G
authors.lastname: Wang
authors.forename: Changlu
authors.initials: C
authors.lastname: Shao
authors.forename: Yichun
authors.initials: Y
authors.lastname: Liu