摘要
使用溶胶-凝胶法制备了Er^(3+)单掺及Er^(3+)/Yb^(3+)共掺La_2TiO_5荧光粉体样品。经过1 100℃下3 h的煅烧,得到了较好的微晶。X射线粉末衍射测试表明样品中不含杂质相。扫描电镜观察表明样品颗粒范围为100~300 nm。紫外激发光谱中,在250~320 nm范围内出现Er离子和临近配位氧离子之间强烈的电荷转移跃迁峰,在350~500 nm出现Er离子f-f跃迁尖锐的吸收峰。在378 nm激发下,Er离子发射强烈的特征绿光(546 nm,~4S_(3/2)-~4I_(15/2)),当Er离子物质的量分数达到1%,发射峰强度达到最大。在980 nm激发下的上转换光谱中,Yb离子的共掺杂有效的敏化上转换发光强度。详细讨论了样品的上下转换发光机理及相应能量传递过程。同时测试了样品的荧光衰减和量子产率。
Er3＋doped and Er3＋/Yb3＋co-doped La2TiO5 phosphors were synthesized by using sol-gel reactions. Good crystallinity was achieved after annealing the samples at 1 100 ℃ for 3 h in air. X-ray powder diffraction results revealed the formation of desired La2TiO5 host with pyrochlore structure. The UV excitation spectra of the samples consist of two regions in which the broad band at 250320 nm originates from the charge-transition（CT）band between Er3＋ion and the nearest neighboring O2-ions and the sharp lines at 350500 nm correspond to the f-f transition of Er3＋ion. Er3＋ion in La2TiO5 emits intense characteristic green light（546 nm,4S3/2-4I15/2） under the excitation at 378 nm and the emission intensity reaches the maximum at Er3＋concentration of 1%（molar fraction）. In the NIR-excited（980 nm） up-converted spectra, Yb3＋ ion as an efficient sensitizer enhanced the emission intensities of Er3＋ion in comparison with those in La2TiO5∶Er3＋phosphors. The luminescence decay curve and quantum yield were also measured and discussed in details.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2016年第1期49-55,共7页
Chinese Journal of Inorganic Chemistry
基金
中央高校基本科研业务费(No.N142304007)
河北省基础研究计划重点基础研究基金(No.15961005D
No.14961108D)资助项目
关键词
铒
镱
钛酸镧
上/下转换
荧光
erbium
ytterbium
La2TiO5
up/down-conversion
luminescence
