摘要
采用高温固相反应法制备了不同浓度Si-N共掺的CaAl2O4:Eu2+蓝色荧光粉,发现只需2%(摩尔分数)的Si-N共掺就可以明显提高荧光粉的荧光性能。研究还发现在CaAl2O4:Eu2+,Sm3+中掺入Si-N后,荧光粉的荧光强度和余辉性能都有提高。通过荧光粉的光谱图,发现共掺没有改变荧光粉中发光中心Eu离子的价态,而电子顺磁共振(EPR)谱则表明,Si-N共掺对Eu离子周围的配位环境产生了较大的影响。这说明掺杂的Si-N倾向于取代Eu2+附近的Al-O,并且由于Si-N键相对于Al-O键具有较短的键长,使发光中心周围晶体骨架的刚性得到了增强,从而减少了晶格热震动导致的非辐射跃迁能量损失,提高荧光粉的发光性能。同时,热释光谱表明,掺杂的Si-N会在发光离子周围产生新的缺陷能级,从而提高荧光粉的余辉性能。
The CaAl2O4： Eu2＋ blue phosphors with varied amount of Si-N co-doping were synthesized through high temperature solid state reaction.The photoluminescence property of phosphor could be significantly improved with only 2% Si-N co-doping.It was also found that the photoluminescence and afterglow performance of CaAl2O4：Eu2＋,Sm3＋ could be improved with Si-N co-doping.It was proved that the co-doping did not affect the valence of the Eu ions with photoluminescence spectra.However,the electron paramagnetic resonance（EPR） spectra showed that the Si-N co-doping greatly impacted the coordination environment around Eu ions,which meant that the Si-N bonds preferred to replace the Al-O bands around the Eu ions.Since the length of Si-N bond was shorter than the length of Al-O bond,the crystal rigidity around Eu ions might be enhanced as a result of the replacement and the non-radiative transitions caused by lattice thermal vibrations shall be reduced.The thermoluminescence spectra showed that the co-doped Si-N has produced a new defect energy level around Eu ions,and enhanced the afterglow performance.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2013年第1期44-48,共5页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金(51072191
11179037)
中国科学院百人计划
关键词
铝酸盐
荧光材料
稀土
Si-N
aluminate
luminescent material
rare earth
Si-N
