不同方法制备Y3 Al5 O12∶Ce3＋黄色荧光粉的对比研究

摘要

Ce3+ doped Y3 Al5 O12 ∶Ce3+ yellow phosphors are prepared by the high-temperature solid-state method,sol-gel method and hydrothermal-pyrolysis methods.The influences of the preparation methods on the phase,morphology and photoluminescence properties of the YAG∶Ce3+ yellow phosphors are investigated by XRD,FESEM and PL,respectively.The results indicate that the three methods all realize the substitution of Ce3+ ions for Y3+ ions,and that the cubic crystalline structure of the Ce3+-doped YAG phosphors is un-changed.The samples prepared by the high-temperature solid-state method present an irregular sphere-like morphology,with a large sample size;the sol-gel method produces nanoparticles with a notable particle ag-glomeration;and the samples prepared by the hydrothermal-pyrolysis method present a well-distributed sphere-like structure with a diameter of 10μm.According to the fluorescence spectrum,the three samples are excited by blue light with a wavelength of 460 nm,and a big broadband emission at 550 nm is observed.How-ever,due to the differences in the morphology and size,these samples present very different luminous intensi-ties and quantum efficiencies .%分别以高温固相法、溶胶-凝胶法和水热-热解法制备了Ce3+掺杂的YAG黄色荧光粉，通过X-射线衍射（XRD）、场发射扫描电镜（FESEM）及荧光光谱（PL）进行表征，考察YAG∶Ce3+黄色荧光粉的晶相、形貌及发光性能对制备方法的依赖性。实验表明，三种方法都实现了Ce3+取代Y3+的位置进入晶格，Ce3+掺杂的YAG荧光粉在晶体结构上都保持立方晶体结构。高温固相法所得样品为不规则球形，粒径尺寸较大；溶胶-凝胶法所得样品为纳米尺度范围，细小颗粒团聚严重，水热-热解法所得样品形貌为球形结构且分散性较好，粒度在10μm左右。荧光光谱显示，三种样品都可被460 nm蓝光有效激发，在550 nm处产生宽带发射，但样品发光强度及量子效率差异较大，该现象主要是由样品形貌及粒径尺寸的差异引起的。