无定型SiO_2对纳米ZnO缺陷发光的辅助增强效应研究  

Auxiliary enhancement for defect luminescence of nano-ZnO with assistance of amorphous SiO_2

作　　者：牛喜平[1] 徐建萍[1] 张晓松[1] 程晓曼[1] 罗程远[1] 李开祥[1] 李岚[1] 

机构地区：[1]天津理工大学材料物理研究所,天津300384

出　　处：《光电子．激光》2012年第8期1509-1512,共4页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(60877029;60977035;60907021;10904109);天津市自然科学基金(11JCYBJC00300;09JCYBJC01400);天津市高等学校科技发展基金计划(20071207);科技创新体系及条件平台建设计划项目"发光材料的制备与性能"(10SYSYJC28100);发光与光信息技术教育部重点实验室开放基金(2010LOI0;2010LOI11)资助项目

摘　　要：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 samples with different sizes were synthesized in the amorphous SiO~ network by hy- drolysis of tetraethyl orthosilicate （TEOS）. X-ray diffraction （XRD） patterns reveal that the average size of nano-ZnO decreases from -14.6 nm to 1.9 nm with the increase of TEOS amount. Photolumineseence （PL） spectra in the visible region show that the peak position presents blue-shift from -560 nm to 510 nm and the emission intensity is significantly enhanced. From analysis of ultraviolet-visible （UV- VIS） absorption spectra, PL spectra and energy-level structure of nano-ZnO and amorphous SiCh, we find that the luminescence enhancement is due to association with the surface bonding on ZnO, which inhibits non-radiative transition process and the reabsorbed process between nano-ZnO and amorphous SiCh. In addition, the reduced distance between photo-induced electrons at nano-ZnO surface and internal oxygen vacancies enhances the radiative transition probability and then the luminescent intensity when the average particle size decreases.

关 键 词：纳米ZNO 无定型SiO2 发光增强 

分 类 号：TN253[电子电信—物理电子学]