铕离子掺杂七铝酸十二钙蓝光发射导电荧光粉的制备及其光学特性

Preparation and Optical Properties of Eu2+ Doped 12CaO·7Al2O3 Blue Emitting Conductive Phosphors

采用碳包埋方法制备了不同Eu^2+掺杂浓度的七铝酸十二钙(C12A7∶x%Eu^2+)导电荧光粉。在254nm的紫外光激发下,样品呈现出位于444nm的蓝光宽带发射峰,其来源于Eu2+的4f65d1-4f7跃迁。当Eu^2+的掺杂浓度为1.0%时,蓝光发射强度最大。通过漫反射吸收光谱结合经验公式可计算C12A7∶1.0%Eu^2+粉末样品的困陷于笼中的电子浓度为3.40×10^19cm^-3。在空气气氛下对C12A7∶1.0%Eu^2+样品进行热处理,通过减少困陷于笼中的电子浓度,即增加困陷于笼中的O^2-离子浓度,可进一步提高样品的发光强度。阴极射线发光实验结果表明:铕掺杂七铝酸十二钙蓝光发射导电荧光粉在低压场发射显示器件中有潜在的应用前景。

Eu^2+ doped 12CaO·7Al2O3 (C12A7∶x % Eu^2+) conductive phosphors with different concentrations were synthesized by a melting solidification method. Upon 254 nm UV excitation,we can observe a broad blue emitting band peaked at 444 nm,which originates from the 4f 65d1-4f7 transition of Eu^2+. As the Eu^2+ doping concentration is 1.0%,the strongest emission intensity can be achieved. The conductive performance of Eu^2+ doped 12CaO·7Al2O3 phosphors can be attributed to the generation of encaged electrons and the calculated encaged electron concentration is ~3.40×10^19 cm^-3 . After the conductive phosphor was annealed in air,its photoluminescence intensity increased with increasing the amount of encaged O^2- anions ( i.e . decreasing the amount of encaged electrons). Our results suggest that C12A7 ∶Eu^2+ blue emitting conductive phosphors have a potential application in field emission displays.