ZnO纳米花的制备及其性能

Preparation and characteristics of ZnO nanoflowers

利用化学气相沉积法,在铜箔上成功制备出形似自然界中刺球花的ZnO纳米花结构.实验进一步研究了氧气和氩气流量比例分别为1:150,1:200,1:250和1:400时对ZnO纳米花结构和性能的影响.结果表明,ZnO纳米花上的ZnO纳米棒的长径比随氧气氛的减少而减小;在氧气和氩气流量比例为1:250时制备出的ZnO纳米花尺寸均匀、形貌均一、花型结构最完美.ZnO纳米花的室温光致发光谱表明,随着氧气氛的减少,可见区域的发光从一个波包变成一个宽峰,且与锌空位相关的缺陷发光峰在减弱,与氧空位相关的缺陷发光峰在增强.基于实验结果,提出了一种在铜箔上制备ZnO纳米花结构的生长模型.

Unlike the general substrates such as SiO_2,ITO,and AZO,the metal foil used as a substrate is rarely studied in application in the substrate,however,it has lots of advantages including cheapness,good conductivity and excellent scalability.In this paper,an acanthosphere-like structure named ZnO nanoflowers is successfully synthesized on Cu foil by using chemical vapor deposition method.The gas flows with oxygen-argon ratios ranging from 1：150,1：200,1：250 to 1：400,which impacted on Cu foil,and the property of the ZnO nanoflowers are carefully studied.The SEM images shown that there are lots of ZnO nanorods grown on the sphere cores,and look like flowers.The ZnO nanoflowers contains uniformly sized ZnO nanorods and morphology with best flower structure when the oxygen/argon gas flow ratio is 1：250.Furthermore,the length-diameter ratio of the ZnO nanorods on the ZnO nanoflowers decreases as the oxygen-argon gas flow ratio decreases.The ZnO is of hexagonal wurtzite structure indicated by XRD pattern and there exist no other diffraction peaks existence except those from the Cu foil.In addition,the photoluminescence of ZnO nanoflower changes from a wave packet into a broad peak in the visible region when the oxygen-argon gas flow ratio between decreases.Further study of the photoluminescence by fitting the peaks in visible region with gaussian function indicates that the photoluminescence relating to the oxygen vacancy defects increases,but that relating to the zinc vacancy defects decreases.Therefore,the white light emitting device may be constructed based on the ZnO nanoflowers studied shown above.Finally,a possible model of the ZnO nanoflowers grown on Cu foil is proposed based on the experimental results.