摘要随着白光LED制备技术的不断发展以及它的应用领域的不断扩展，白光LED用荧光粉的性能和制备越来越受到人们的重视。尤其是可被蓝光和紫外光激发的红色荧光粉的性能直接影响着白光LED的显色性。本文利用高温固相反应法制备了一种性能稳定的红色荧光粉Sr2SiO4:Sm3+,并利用电荷补偿和共掺杂离子对所制备的红色荧光粉的发光性能进行了改进，得到了发光强度更高的红色荧光粉。Sr2SiO4:Sm3+荧光粉的发射光谱由位于红橙区的3个主要荧光发射峰组成，峰值分别于570nm，606nm和653nm，对应了Sm3+的4G5/2→6H5/2，4G5/2→6H7/2和4G5/2→6H9/2特征跃迁发射，606nm的发射最强。激发光谱表现从350nm到420nm的宽带，可以被近紫外光辐射二极管管芯产生的350～410nm辐射有效激发。研究了Sm3+掺杂，反应温度和不同电荷补偿剂对样品发光亮度的影响，Sm3+掺杂摩尔分数为5%、电荷补偿剂为Cl–时的效果最好。Sr2SiO4:Sm3+是一种适用于白光LED的红色荧光粉。74177
毕业论文关键词：白光LED；硅酸锶；发光性质；红色荧光粉；电荷补偿剂
Abstract The fabrication and properties of phosphor used for whit LED were paid more attention with the extension of applied field and the development of preparation technology in white LED。 Especially, the properties of phosphor excited by blue and UV light can effect directly the color rendering of white LED。
A novel stable red phosphor Sr2SiO4:Sm3+was prepared by solid state method。 The properties of this phosphor were improved using charge compensation。 The emission spectrum of Sr2SiO4:Sm3+ consists of three major orange-red emission bands。 The emission peaks are located at 570, 606 nm and 653 nm, corresponding to the 4G5/2→6H5/2, 4G5/2→6H7/2 and 4G5/2→6H9/2 typical transitions of Sm3+ respectively and the strongest one appears at 606 nm。 Its excitation spectrum extends from 350nm to 420nm, which indicates that this phosphor can be excited effectively by near-ultraviolet light-emitting diodes (UVLED)。 The influences of charge compensators, the reaction temperature and the concentration of Sm3+on the emission intensity were also investigated。 When the dosage of Sm3+ in mole fraction is 5% and the charge compensator is Cl–, the strongest emission is obtained。 Sr2SiO4:Sm3+ phosphor is a very appropriate red-emitting phosphor for white light-emitting diodes。
Key words: White LED; Strontium silicate; Luminescence property; Red phosphor;Charge compensator
目 录
1 绪 论 5
1。1 发光二极管的历史 5
1。2 单色LED发光机理 5
1。3 荧光粉的发光机理和制备方法 6
1。3。1 发光和发光材料。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。6
1。3。2 发光的主要特征 7
1。4 研究目的、内容与创新点。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。10
1。4。1 研究的目的与意义 10
1。4。2 研究内容。。 。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。10
1。4。3 创新点 12
2 实验内容 12
2。1 实验仪器 12
2。2 实验试剂 12
2。3 实验流程 LED用红色发光粉Sr2SiO4的制备及性能研究:http://www.youerw.com/wuli/lunwen_84689.html