SrAl_2Si_2O_8:Eu^(2+)蓝色荧光粉制备条件优化及助熔剂作用研究

Study on the Optimized Conditions of Preparation of SrAl_2Si_2O_8:Eu^(2+) Blue Light Emitting Phosphor and Role of Flux

采用高温固相法在弱还原气氛下制备SrAl2Si2O8∶Eu2+系列荧光粉,研究了预烧温度、预烧时间、烧成温度和助熔剂用量对发光性能的影响;正交试验得出最佳制备条件为:经1050℃预烧180 min,在1300℃,240 min烧成,硼酸加入量6.0 wt%。XRD分析表明,所制得样品属于单斜晶系。激发光谱位于220~400 nm,可拟合成四个峰,表观峰值位于350 nm;发射光谱位于370~600 nm,可由406 nm和441 nm两峰拟合而成,表观峰值位于408 nm。随着硼酸用量的增加,试样衍射峰半高宽变窄和强度增强,晶胞参数a、b、c和晶胞体积V减小,硼酸起到助熔剂和基质组分置换双重作用。

A series of luminescence phosphors SrAl2Si2O8∶Eu2＋ were prepared via solid-state reaction in weak reductive atmosphere.The effect of the first firing temperature（FFTE）,the first firing time（FFTI）,the second firing temperature（SFTE） and the concentration of flux H3BO3（CFB） on the spectrum characteristics and structure of the sample were investigated.It was shows that the best luminescence capability of the sample SrAl2Si2O8∶Eu2＋ is ignited firstly at 1050 ℃ for 180 min and secondly at 1050 ℃ for 240 min with a concentration of 6.0 wt% H3BO3.X-ray diffraction（XRD） patterns disclosed that the superfine SrAl2Si2O8∶Eu2＋ exhibites a monoclinic crystal structure.A broad excitation spectrum consists of four excitation bands,which locate between 220 nm and 400 nm,the maximum emission wavelength is 352 nm.The emission spectrum,which is a broad band between 370 nm and 600 nm,can be fitted by two peaks at 406 nm and 441 nm and its apparent peak is at 408 nm.With boric acid content increasing,XRD patterns intensity increase while FWHM of XRD patterns,the lattice parameters（a,b,c） and unit cell volume of phosphor SrAl2Si2O8∶Eu2＋ decrease.