H_3BO_3掺杂量对Sr_3Al_2O_6:Eu,Dy红色长余辉发光材料性能的影响

Influence of H_3BO_3 Doping on Properties of Sr_3Al_2O_6:Eu,Dy Phosphor

采用高温固相法制备了Sr3Al2O6:Eu2+,Dy3+红色长余辉发光材料,研究了H3BO3掺杂量对其性能的影响。利用X射线衍射仪对材料的物相进行了分析,结果表明,1 200℃下制备的不同H3BO3掺杂量样品的物相为Sr3Al2O6;采用荧光分光光度计、照度计测定了样品的发光特性,结果表明Sr3Al2O6:Eu2+,Dy3+的激发峰位于472 nm的宽带谱,发射峰为位于612 nm的宽带谱,对应于Eu2+的4f65d1→4f7的跃迁;H3BO3的加入在促进产物晶化的同时,还可改变进入晶格中的Eu、Dy离子的浓度,从而改善余辉特性。余辉测试表明,Sr2.95Al1.8O6:0.02Eu2+,0.03Dy3+,0.2B3+的余辉时间最长,可达620 s(≥1 mcd/m2)。

The red long afterglow phosphors Sr3Al2O6-Eu, Dy were prepared by solid-state reaction. The crystal structures were characterized by X-ray diffraction（XRD）. The results reveal that the samples prepared at 1 200℃ are composed of single Sr3 Al2O6 phase. The excitation, emission and afterglow spectra were investigated by fluorescence spectrophotometric techniques. The samples exhibite red light emission with the main emission peak at 612 nm under an excitation of 473 nm. The red emission has a broad-band feature, belonging to the emission of the 4f^6 5d^1→4f^7 of Eu2＋ ions. The addition of H3BO3 reduces the synthesizing temperature. Volatilization and crystallization of the amorphous boundary phase at high temperature facilitate the diffusion of Eu and Dy into Sr3 Al2O6 host by decreasing the amount of grain boundary phase as well as increasing the concentration of Eu,Dy. The afterglow time of the Sr2.95 Al1.8 O6：0.02Eu^2＋ ,0. 03Dy^3＋ ,0.2B^3＋ phosphors lasts for 620 s（≥1 mcd/m2） after removal of exciting source.