发光学报, 2010, 31 (2): 181, 网络出版: 2010-05-31
紫外激发的LiCaPO4∶Eu2+蓝色发光粉的发光特性
Optical Properties of Eu2+-activated Blue-emitting Phosphor LiCaPO4 under Ultraviolet Excitation
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470 nm,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250~440 nm光有效激发,这与紫外发光二极管的发射光谱(350~410 nm)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。
Abstract
A novel blue-emitting phosphor LiCaPO4∶Eu2+ 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 4f65d1→4f7 transition of Eu2+. Comparing with LiSrPO4∶Eu2+ and NaBaPO4∶Eu2+, the emission spectrum shows a red shift obviously. It is caused by the decrease of cationic radii which change the degree of Eu2+ 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 Eu2+ content on the emission intensity of LiCaPO4∶Eu2+ was also investigated. Different Eu2+ 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 Eu2+ content, and the optimal doping content is 5%. Concentration quenching occurs when the Eu2+ content is beyond 5%, as a result of multipole-multipole interaction. The LiCaPO4∶Eu2+ phosphor is a potential blue-emitting phosphor for white-emitting LEDs.
杨志平, 王凤和, 郭颖楠, 李旭, 马欣, 闻建伟. 紫外激发的LiCaPO4∶Eu2+蓝色发光粉的发光特性[J]. 发光学报, 2010, 31(2): 181. YANG Zhi-ping, WANG Feng-he, GUO Ying-nan, LI Xu, MA Xin, WEN Jian-wei. Optical Properties of Eu2+-activated Blue-emitting Phosphor LiCaPO4 under Ultraviolet Excitation[J]. Chinese Journal of Luminescence, 2010, 31(2): 181.