Ca_(0.88)TiO_3∶0.12Eu^(3+)红色荧光粉的结构与发光性能

Structural and Optical Properties of Ca_(0.88)TiO_3∶0.12Eu^(3+) Red Phosphors

采用固相反应法制备Ca0.88TiO3∶0.12Eu3+(CTE)红色荧光粉,研究了CTE荧光粉的结构与发光性能。XRD结果表明,不同退火温度下的CTE荧光粉皆为钙钛矿结构,其晶粒尺寸随退火温度的升高而增大,1 300℃退火时晶相最佳,与SEM观察的结果相一致。CTE荧光粉的激发光谱由350~500 nm范围内的一系列窄带吸收峰组成,其中的最强峰位于398 nm附近;发射谱主要包含595 nm和616 nm两个峰,属于Eu3+离子跃迁发光。616 nm发射峰明显强于595 nm发射峰,说明Eu3+是处在无反演对称中心的格位。CTE荧光粉的发光随着退火温度的升高而增强,1 300℃时达到最大值,这可归因于其结晶状况的改善。另外,CTE荧光粉还具有色纯度高与热稳定性好等优点,这些将使CTE成为一种潜在的用于近紫外激发的白光LED红色荧光粉材料。

Red phosphors of Ca0.88TiO3∶0.12Eu3+(CTE) were synthesized by solid-state method,and their structure and morphology were studied.XRD results show that CTE phosphors sintered at different temperature exhibit orthorhombic structure.The average grain size increases with the increase of sintering temperature,and their crystallization sintered at 1 300 ℃ is the best,which is consistent with the SEM results.CTE phosphors can be efficiently excited by near-ultraviolet light of 398 nm,and emit intensive red light with peaks around 594 nm and 616 nm corresponding to the transition 5D0→7F1and5D0→7F2of Eu3+.The peak around 616 nm is stronger than that of 594 nm,showing that Eu3+ ions site at lattice without the center of inversion symmetry.The emission intensity of CTE phosphor increases with the sintering temperature,and is the highest when the sintering temperature is 1 300 ℃ due to higher crystallinity.Furthermore,CTE phosphors have very good thermal stability and high color purity,implying the potential to be a promising red phosphor in white light emitting diodes.