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利用正硅酸乙酯水解后的无定型SiO2网络结构,合成了不同尺度的纳米ZnO。X射线衍射(XRD)谱显示,当正硅酸乙酯的量从0ml增加到5ml,ZnO的粒径从14.6nm减小到1.9nm;光致发光(PL)光谱显示,发射峰位从560nm蓝移到510nm,发射强度明显增强。利用紫外-可见(UV-VIS)吸收光谱、PL光谱以及能级结构分析,我们认为,纳米ZnO随尺度下降所产生的发光增强来源于无定形SiO2所抑制的ZnO表面非辐射跃迁过程以及二者之间的再吸收过程;此外,纳米ZnO尺度的下降,使得其表面的光生电子和晶格内部的O空位(Vo)之间的距离减小,提高了辐射跃迁的几率也是获得高荧光效率的可能原因。
Nano-ZnO with different scales was synthesized by using the amorphous SiO2 network structure hydrolyzed by tetraethyl orthosilicate. X-ray diffraction (XRD) spectra showed that the particle size of ZnO decreased from 14.6nm to 1.9nm when the amount of tetraethyl orthosilicate was increased from 0ml to 5ml. The photoluminescence (PL) spectra showed that the emission peak shifted from 560nm Blue shift to 510nm, emission intensity was significantly enhanced. Using UV-VIS absorption spectra, PL spectra and energy level structure analysis, we believe that the luminescence enhancement of nano ZnO with the decrease of scale comes from the non-radiative transition of ZnO surface suppressed by amorphous SiO2 and both In addition, the decrease of the size of nano-ZnO makes the distance between the photoelectrons on the surface and the O vacancy (Vo) in the crystal lattice decrease, and the probability of increasing the radiation transition is also high fluorescence efficiency Possible Causes.