MAl_2O_4∶Eu^(3+)红色荧光粉的制备及其发光性质研究

Synthesis and luminescent properties of MAl_2O_4∶ Eu^(3+)( M =Ca,Sr,Ba) red phosphor

采用溶胶-凝胶法分别制备MAl2O4∶Eu3+(M=Ca,Sr,Ba)系列红色荧光粉,并对所制备的样品进行了XRD、SEM以及荧光光谱等表征,结果表明:CaAl2O4∶Eu3+红色荧光粉的适宜焙烧温度为900℃,其粒径大小约1~2μm,当激活剂Eu3+的摩尔浓度增加到4%时,其发光强度达到最大;SrAl2O4∶Eu3+红色荧光粉的适宜焙烧温度为1 100℃,其粒径大小约3~4μm,当激活剂Eu3+的摩尔浓度增加到4%时,其发光强度达到最大;BaAl2O4∶Eu3+红色荧光粉的适宜焙烧温度为1 100℃,其粒径大小约4~5μm,当激活剂Eu3+的摩尔浓度增加到2%时,其发光强度达到最大。以392 nm的近紫外光激发样品,MAl2O4∶Eu3+(M=Ca,Sr,Ba)荧光粉发出明亮的红光,这对应于Eu3+的4f-4f跃迁。MAl2O4∶Eu3+在392 nm的吸收与目前应用的紫外光发光二极管(LED)芯片相匹配,因此,MAl2O4∶Eu3+(M=Ca,Sr,Ba)荧光粉在作为白光LED用红色荧光粉方面具有潜在的应用前景。

MAl2O4∶ Eu3 ＋（ M =Ca,Sr,Ba） red phosphors were synthesized by sol-gel method respectively. The optimum calcinations temperature for CaAl2O4∶ Eu3 ＋phosphor is 900 ℃,the size of the particles are about 1 ～ 2 μm,and the luminous intensity reaches the maximum when the mol concentration of activator Eu3 ＋ions increased to 4%; the optimum calcinations temperature for SrAl2O4∶ Eu3 ＋red phosphor is 1 100 ℃,the size of the particles are about 3 ～ 4 μm,and the luminous intensity reaches the maximum when the mol concentration of activator Eu3 ＋ions increased to4%; the optimum calcinations temperature for BaAl2O4∶ Eu3 ＋Red Phosphor is 1 100 ℃,the size of the particles are about 4 ～ 5 μm,and the luminous intensity reaches the maximum when the mol concentration of activator Eu3 ＋ions increased to 2%. Upon excitation with 392 nm light,all the MAl2O4∶ Eu3 ＋（ M =Ca,Sr,Ba） powders show bright red emission due to the 4f-4f transitions of Eu3 ＋ions. The excitation and emission spectra showed that the phosphor can be effectively excited by ultraviolet light（ 392 nm）,nicely fitting in with the widely applied emission wavelengths of ultra-violet light-emitter diodes（ LED） chips. The MAl2O4∶ Eu3 ＋（ M = Ca,Sr,Ba） phosphors may be good candidate phosphor for LED application.