摘要
以柠檬酸为螯合剂,采用沉淀法制备了稀土Tb3+掺杂的ZnWO4绿色荧光粉前驱体。通过差热分析(DTA)、热重分析(TG)、X射线衍射(XRD)等手段对产物进行了表征。结果表明,当退火温度低于700℃时,得到的样品为非晶态,而高于850℃退火处理后为单斜结构。使用荧光分光光度计研究了Tb3+在ZnWO4基质中的发光性质。结果显示,ZnWO4:Tb3+样品在544nm波长光的监测下于200~300nm处出现由W→O及Tb→O跃迁共同作用产生的重叠激发峰和系列Tb3+的f-f跃迁锐峰,其中位于488nm处的激发峰非常显著,对应于Tb3+的7F6→5D4跃迁。说明该法制备的荧光粉ZnWO4:Tb3+能够被蓝光有效激发,可以与广泛使用的蓝光LED芯片的输出波长相匹配。在488nm波长光的激发下观察到ZnWO4粉末中Tb3+的544nm(5D4→7F5)强的特征发射,说明ZnWO4:Tb3+粉末可作为白光LED的绿色补偿荧光粉。当以267nm激发ZnWO4:Tb3+时,有宽的WO2-4特征发射峰和Tb3+的5D4→7F6及5D4→7F5跃迁产生的发射峰,随着Tb3+掺杂浓度的增加,WO2-4的特征发射强度逐渐降低,而Tb3+的5D4→7F5跃迁强度增大,表明Tb3+与WO2-4之间有能量转移。
The green-light phosphor ZnWO4 doped with rare earth Tb3 ＋ was prepared by precipitation method using citric acid as che- late reagent. The structure of products was characterized by differential thermal analysis （DTA）, thermogravimetry analysis （TGA） , X-ray diffraction （XRD）, etc. The results showed that the sample was non-crystalline when the annealing temperature was below 700 ℃ ; however, when the temperature was above 850 ℃ , the monoclinic phase structure formed. Fluorescence spectrophotometer was used to study the fluorescence properties of Tb3 ＋ in ZnWQ powder. The results showed that ZnWQ 4Tb3＋ samples in the monitoring of 544 nm light wave appeared overlapping peaks generated by W→O and Tb→O transitions interaction excitation and series of f-f transi- tion sharp peaks of Tb3 ＋ at 200 ~ 300 nm, and the excitation peak at 488 nm was very significant, corresponding to the Tb3 ＋ 7 F6→5 D4 transition. It indicated that the fluorescent powder of ZnWQ 4 Th3 ＋ prepared by this method could be stimulated effectively by blue light and could match the wavelength of blue lighting emitting diode （LED） chip which was widely used. The characteristic emission of Tb3＋ at 544 nm （5 D4→7 F5 ） observed in ZnWO4 powder under the activation of 488 nm light wave indicated that ZnWO4 ：Tb3＋ powder could be used as the green phosphor compensation for white light LED . When ZnWO4 ：Tb3＋ was excited by the light with wavelength of 267 nm, broad characteristic excitation peaks of WO2/4- and emission peaks by Tb3 ＋ 5 D4 →7 F6 and 5 D4→7 F5 were observed ; with the increase of Tb3＋ concentration, the characteristic emission intensity of WO2/4- decreased gradually while the transition intensity of 5D→7F5 of Tb3＋ increased, which indicated that a significant energy transfer occurred between Tb3 ＋ and WO2/4.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2015年第2期130-135,共6页
Chinese Journal of Rare Metals
基金
内蒙古自治区自然科学基金项目(2010MS0219)
内蒙古自治区高等学校科学研究重点项目(NJZZ12030)资助
