Growth mechanism, photoluminescence, and field-emission properties of ZnO nanoneedle arrays.
ZnO nanoneedle arrays have been grown on a large scale with a chemical vapor deposition method at 680 degrees C. Zn powder and O(2) gas are employed as source materials, and catalyst-free Si plates are used as substrates. Energy-dispersive X-ray and X-ray diffraction analyses show that the nanoneedles are almost pure ZnO and preferentially aligned in the c-axis direction of the wurtzite structure. The growth mechanism of ZnO nanoneedle arrays is discussed with the thermodynamic theory and concluded to be the result of the co-effect of the surface tension and diffusion. Photoluminescence spectrum of the as-grown products shows a strong emission band centering at about 484 nm, which originates from oxygen vacancies. Field-emission examination exhibits that the ZnO nanoneedle arrays have a turn-on voltage at about 5.3 V/microm.
Zhang
Zengxing
Z
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100080, P. R. China.
Yuan
Huajun
H
Zhou
Jianjun
J
Liu
Dongfang
D
Luo
Shudong
S
Miao
Yanming
Y
Gao
Yan
Y
Wang
Jianxiong
J
Liu
Lifeng
L
Song
Li
L
Xiang
Yanjuan
Y
Zhao
Xiaowei
X
Zhou
Weiya
W
Xie
Sishen
S