新穎硼酸鹽與鋁酸鹽螢光體之製備與發光特性之研究

Abstract

本研究以固態合成法成功合成出A、B、C、D、E、F、LiAl5O8與LiAlO2等八種不同螢光體主體，所有主體中皆分別摻入Ce3+、Eu2+或Mn4+作為活化劑以取代各主體中Ca2+、Sr2+、Ba2+或Al3+等格位，經X光繞射分析以確認主體晶相不因Ce3+、Eu2+或Mn4+之摻入而改變光繞射，漫反射光譜確認主體在Ce3+、Eu2+或Mn4+的激發波段並無吸收，所有光學特性來自稀土離 子。 稀土離子(或過渡金屬)所取代格位的配位數介於四至九之間，而Ce3+發光波長介於403 nm至423 nm之間是為藍光放射；Eu2+離子發光波長為494 nm之綠光放射；過渡金屬Mn4+的發光波長則位在667 nm至715 nm之間。此外，本研究亦進行螢光粉色度座標量測，上述螢光粉分別發射紫藍光、藍光、綠光以及高飽和度紅光等色光，除可提供LED製作中螢光粉應用的新選擇之外也避開了專利的束縛，部分更具 有照明應用的潛力。

Novel phosphors with compositions of A,B,C,D,E,F, LiAl5O8：Mn4+,and LiAlO2：Mn4+ were synthesized by solid state method. The crystal structure of host materials were found to retain after doping of rare earth ions by comparing X-ray data of the samples to those reported in database. Through the measurements of diffuse reflectance spectra for both doped and un-doped samples, we found that all of the optical emissions were resulted from the doped rare earth ions. We have also analyzed the structure of the hosts and relevant luminescence behaviors. In this research, rare-earth ions were found to substitute and enter the cation siteswith four to nine in coordination numbers. The emission wavelength werefound from 403 nm to 423 nm as in the case of Ce3+-doped phosphors showing a blue emission and 494 nm as in Eu2+-doped phosphors showing a green emission and 667 nm to 715 nm as in Mn4+-doped phosphors showing characteristically highly saturated red emission. Additionally, the C.I.E. chromaticity coordinates show that these phosphors emit hues including violet, blue, green, and red, respectively.