红色荧光粉Ca_3B_2O_6:Eu~(3+)的制备及发光性能

采用高温固相法合成了Ca3B2O6:Eu3+红色荧光粉,并对其发光性质进行了研究.样品的激发光谱由位于220~350 nm的带状谱和350~500 nm的一系列窄带组成,这些窄带是由Eu3+的f-f跃迁引起的,光谱峰值分别为280,396和469 nm.它可以被近紫外光辐射二极管管芯产生的350~410 nm辐射有效激发.用396 nm激发得到样品的发射光谱,峰值位于578,590,610,618和650 nm,分别由Eu3+离子的5D4→7FJ(J=0,1,2,3)跃迁引起的.研究了Eu3+离子浓度和电荷补偿剂对发射光谱的影响.结果显示随着Eu3+浓度增加,发光强度逐渐增强,未发现浓度猝灭现象.掺入Li+,Na+,K+3种离子作为电荷补偿剂,均提高了样品的发光强度,其强度从大到小依次为I(Li+)I(Na+)I(K+),说明Li+是最佳的电荷补偿剂.

Preparation and Luminescent Properties of Ca_3B_2O_6:Eu~(3+) Red Phosphor

Ca_3B_2O_6:Eu~(3+) red phosphor was synthesized by high temperature solid state reaction and its luminescent properties were investigated. XRD analysis indicated the pure Ca_3B_2O_6:Eu~(3+) crystallite was obtained at 1 100 ℃ for 2 h. Excitation spectrum consists of wide band located at 220 to 350 nm and a series of narrow bands located at 350 to 500 nm which are attributed to f-f transitions of Eu~(3+) ion. The peaks of excitation spectra are 280, 396 and 469 nm, respectively. This phosphor can be excited effectively by near-ultraviolet light-emitting diodes (UVLED). The peaks of emitting spectra are 578,590,610,618 and 650 nm, corresponding to ~5D_4→~7F_J(J=0,1,2,3)typical transitions of Eu~(3+), respectively. The effects of charge compensations and the molar concentration of Eu~(3+) on the emission intensity were also studied. The intensity of Ca_3B_2O_6:Eu~(3+) was improved obviously with the increasing concentration of Eu~(3+), but the concentration quench did not observed. The role of charge compensations of Li~+, Na~+ and K~+ ions can all increased the luminescent intensity of Ca_3B_2O_6:Eu~(3+). Li~+ ion gave the best improvement to enhance the intensity of the emission obviously. Li~+ ion is the optimal charge compensation.