S引入ZnO的水热生长及其微观发光特性研究

Hydrothermal growth of sulfur introducted ZnO and its luminescence properties on the microscale

利用单步水热法制备了纯ZnO和S引入的双棒状ZnO(S-ZnO)孪晶结构,并系统研究了掺杂对ZnO结构、形貌及荧光发光特性的影响。X射线衍射的实验结果表明,在引入S的ZnO样品中没有出现可以检测的新物相,S在样品中主要以杂质的形式存在。荧光光谱数据表明,在低温下纯ZnO样品无可见光发光,但S-ZnO样品出现了较强的绿光发光峰;室温下两个样品均出现了可见光发光:ZnO样品的发光峰位于橙光区(570 nm附近),而S-ZnO位于绿光区(500 nm附近)。微区阴极荧光谱的数据表明,ZnO样品的橙光发光非常弱,几乎不可探测;S-ZnO样品的绿光发光则很强,要远远超过带边发光。本研究结果为进一步理解S在ZnO中引入的缺陷及其发光机理起到重要的作用,对增强ZnO的可见光发光特性进行了有益的探索。

Double-rod shaped pure ZnO and sulfur Introducted ZnO (S-ZnO) samples with twin crystal structure have been synthesized by a one-step hydrothermal method, and the effects of sulfur doping on the structure, morphology, and fluorescence behavior of resulted samples were systematically studied. XRD results showed that no new phase appeared in S-ZnO samples and the sulfur existed just as the dopant in the samples. Photoluminescence (PL) results at low temperature showed that there was no visible light emission for pure ZnO samples, while strong green light emission peaks appeared for the S-ZnO samples. When PL was measured at room temperature, both samples showed visible emissions: orange light emission (570 nm) for ZnO and green light emission (500 nm) for S-ZnO. Micro-zone cathodoluminescence (CL) results gave an almost undetectable orange light emission for ZnO samples, but for S-ZnO samples, the green light emission was stronger and its intensity was higher than near-band-gap emission. The results of this study play an important role on further understanding the defects caused by the introduction of sulfur into ZnO and its luminescence mechanism, making a useful and beneficial exploration to enhance the visible light emission characteristics of ZnO.