摘要
采用高温固相法合成了LiCaPO4:Eu2+蓝色发光粉,并对其发光特性进行了研究。该发光粉发射峰值位于470nm,属于Eu2+的4f65d1→4f的特征跃迁发射,与结构相似的LiSrPO4:Eu2+和NaBaPO4:Eu2+相比其峰值有明显红移。Eu2+在LiCaPO4晶体中可被250～440nm光有效激发,这与紫外发光二极管的发射光谱(350～410nm)匹配。考察了Eu2+的掺杂浓度对发光强度的影响,最佳掺杂摩尔分数为5%,摩尔分数超过5%后发生猝灭现象。浓度猝灭机理为电多极-电多极的交互作用。LiCaPO4:Eu2+是适合UV-LED管芯激发的白光发光二极管用高亮度蓝色发光粉。
A novel blue-emitting phosphor LiCaPO4：Eu^2＋ for LEDs was prepared by high temperature solid-state reaction and its luminescent properties were investigated.The emission spectrum shows a single intense band centered at 470 nm,which corresponds to the 4f^65d^1→4f^7 transition of Eu^2＋.Comparing with LiSrPO4：Eu^2＋ and NaBaPO4：Eu^2＋,the emission spectrum shows a red shift obviously.It is caused by the decrease of cationic radii which change the degree of Eu^2＋ energy splitting and affect the electron cloud expansion.The excitation spectrum is a broad band extending in 250～440 nm,which matches the emission of ultraviolet light-emitting diodes （UV-LEDs） well.The effect of doped Eu^2＋ content on the emission intensity of LiCaPO4：Eu^2＋ was also investigated.Different Eu^2＋ contents have little effort on the emission spectrum,but the emission intensity shows a great different.The emission intensity is enhanced with the increase of the Eu^2＋ content,and the optimal doping content is 5%.Concentration quenching occurs when the Eu^2＋ content is beyond 5%,as a result of multipole-multipole interaction.The LiCaPO4：Eu^2＋ phosphor is a potential blue-emitting phosphor for white-emitting LEDs.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2010年第2期181-184,共4页
Chinese Journal of Luminescence
基金
河北省自然科学基金(F2009000217)资助项目
