摘要:
三基色荧光粉中,红色荧光粉性能较差.为获得性能优良的红色荧光粉,本文采用高温固相法合成了Eu2+,Cr3+单掺杂及共掺杂的碱土金属多铝酸盐MAl12O19(M=Ca,Sr,Ba)发光体.实验表明,在以上三种基质中均存在Eu2+→Cr3+的能量传递,利用能量传递可以有效地将Eu2+的蓝光或绿光转换为红光.三种碱土金属多铝酸盐基质的晶体结构相似,但Eu2+,Cr3+发光受晶体场影响,导致在不同的基质中Eu2+,Cr3+间能量传递效率不同.通过光谱分析及能量传递效率计算发现,相同掺杂浓度下,CaAl12O19中Eu2+→Cr3+的能量传递效率最高,SrAl12O19次之,BaAl12O19最低.红光转换率在CaAl12O19中最高.
Abstract:
We synthesize MAl12O19(M = Ca,Sr,Ba) singly doped with Eu2+ or Cr3+ and co-doped with Eu2+ and Cr3+ by hightemperature solid-state reaction under reducing atmosphere.It is observed that there exit energy transfers from Eu2+ to Cr3+ in MAI12O19(M = Ca,Sr,Ba) hosts.Although the MAl12O19(M= Ca,Sr,Ba) hosts have similar crystal structures,the energy transfer efficienies and the conversion rates of the blue light to the red light are different.Both experiment and calculation show that the energy transfer from Eu to Cr in CaAl12O19 host is most efficient,and the ratio of the red emission to the blue emission in CaAl12O19 host is the highest among the three different hosts.