花状纳米结构ZnS:Cu的制备与光学性质研究

Synthesis and luminescence properties of ZnS:Cu with flower-like nanostructure

采用水热法合成了具有花状纳米结构的ZnS:Cu粉末。利用X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)和荧光光谱仪研究了在不同正硅酸四乙酯(TEOS)含量的条件下制备的样品的物相、形貌与光致发光(PL)性质。测试结果表明:制备的ZnS:Cu样品都具有立方相闪锌矿结构;由于TEOS分子的影响,制备的样品不再是微球状,而是由厚度为30 nm的纳米片组成的花状纳米结构;随着TEOS含量的增加,样品的PL光谱强度先增强后减弱。此外,样品的发光峰波长保持在560 nm,分析其发光机理为硫空位到Cu的t2能级的跃迁。

The ZnS：Cu powders with flower-like nanostructure were synthesized via hydrothermal method. X-ray diffraction （XRD）, field-emission scanning electron microscopy （FESEM）, transmission electron microscopy （TEM） and luminescence spectrometer were used to characterize the phase, morphology and photoluminescence （PL） properties of samples prepared with different contents of tetraethyl orthosilicate （TEOS）. The results show that all ZnS：Cu samples possess cubic sphalerite structure. Because of the effect of TEOS, the synthesized samples are not microspheres but flower-like nanostructures which are composed of ZnS：Cu nanosheet with an average thickness of 30 nm. With the increase of content of TEOS, the intensity first of PL spectra increases first, and then decreases. Moreover, the PL emission peak keeps at 560 nm and it is concluded that the luminescence mechanism is attributed to the transition from sulfur vacancies to t2 states of Cu.