摘要
白光LED由于发光效率高、寿命长以及节能环保等优点,已逐渐成为照明行业的主流产品。通常照明用白光LED要求高显色指数和低色温。本文采用Gd3(Al,Ga)5O12∶Ce(GGAG∶Ce)作为发光粉体、硅胶作为基质材料成功制备了可用于封装白光LED的具有一定透明度的GGAG∶Ce柔性复合荧光膜。通过X射线衍射(XRD)、荧光光谱、扫描电子显微镜(SEM)、变温荧光光谱等手段分析了复合荧光膜的物相、形貌及发光性能。结果表明,该柔性复合荧光膜的主晶相为GGAG∶Ce晶相,荧光膜表面平整度较好、柔性较好。GGAG∶Ce复合荧光膜的主激发峰和发射峰分别位于450 nm和540 nm左右,属于Ce^(3+)的5d→4f电子跃迁发光,衰减时间约为40 ns左右。荧光性能表明,复合荧光膜的最佳复合浓度为20%左右,其显色指数达到85.1,色温为6295 K。变温荧光光谱表明,复合荧光膜具有较好的热稳定性,在白光LED中具有潜在的应用前景。
White LED has gradually become a mainstream product in the lighting industry due to its high luminous efficiency,long life,energy saving and environmental protection.Generally,white light LEDs for lighting are required to have high color rendering index and low color temperature.In this paper,the GGAG∶Ce nano-powder was synthesized by chemical co-precipitation method.And the translucent Gd3(Al,Ga)5O12∶Ce(GGAG∶Ce)flexible composite fluorescent film was prepared successfully by uniformly dispersing the GGAG∶Ce nano-powder into the silica gel matrix,which can be used for white light LEDs.The phase construct,morphology and luminescence properties of the composite fluorescent film were discussed by X-ray diffraction(XRD),fluorescence spectroscopy,scanning electron microscope(SEM),and variable temperature fluorescence spectroscopy.The results show that the main crystal phase of composite fluorescent film is GGAG∶Ce crystal phase.The main excitation peak and emission wavelength of the GGAG∶Ce composite fluorescent film are located at 450 nm and 540 nm,respectively,which belong to the 5d→4f electronic transition of Ce^(3+),and the decay time is about 40 ns.Fluorescence performance shows that the optimal composite concentration of the composite fluorescent film is about 20%,its color rendering index reaches 85.1,and its color temperature is 6295 K.The variable temperature emission spectra present the composite fluorescent film has a good thermostability,which has potential application prospects in white LEDs.
作者
张伟杰
魏钦华
唐高
陈振华
秦来顺
ZHANG Wei-jie;WEI Qin-hua;TANG Gao;CHEN Zhen-hua;QIN Lai-shun(School of Materials and Chemistry, China Jiliang University, Hangzhou 310018, China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2021年第4期478-485,共8页
Chinese Journal of Luminescence
基金
国家自然科学基金(11975220,51972291)资助项目。
