蓝绿双色可调荧光粉Ba_2Ca(BO_3)_2:Ce^(3+),Eu^(2+),Na^+的发光性能和能量传递研究

Luminescence Properties and Energy Transfer of Tunable Blue-Green Two-Color Phosphor Ba_2Ca(BO_3)_2:Ce^(3+),Eu^(2+),Na^+

用高温固相法制备了蓝绿双色可调荧光粉Ba2Ca(BO3)2:Ce3+,Eu2+,Na+,并研究了其发光特性。在345 nm近紫外光激发下发射的分别以390和410 nm为主峰的蓝光发射带对应于Ce3+的5d→2F5/2和5d→2F7/2跃迁,峰值位于525 nm的绿光发射带归属于Eu2+的4f65d1→4f7跃迁。通过Dexter共振能量传递理论和Reisfeld近似计算得到2种离子之间存在四极矩-四极矩能量传递。当Ce3+和Eu2+的摩尔浓度分别为5%和4%时,样品的色坐标位置落在蓝绿色区域,并可以通过改变基质中Ce3+和Eu2+的摩尔比来调节荧光粉的色坐标。Ba2Ca(BO3)2:Ce3+,Eu2+,Na+是一种适用于近紫外芯片的新型双色可调谐白光LED用荧光粉。

Ba2Ca（BO3）2：Ce3＋, Eu2＋, Na＋ phosphor was synthesized by a solid-state reaction method. The luminescence of the phosphor shows tunable blue-green two-color emission bands under the radiation of 345 nm. The blue emission bands with peak center at 390 nm and 410 nm were corresponding to the transition of 5d → 2F5/2 and 5d → 2F7/2 of Ce3＋, respectively, while the green emission peaking at 525 nm was corresponding to the transition of 4f65d1 → 4f7 of Eu2＋. Moreover, the energy transfer mechanism of quadrupole-quadrupole interaction was deduced by Dexter resonance energy transfer theory and Reisfeld approximation calculation. The CIE chromaticity coordinate of the phosphor fell in the blue-green region, when the concentration of Ce3＋ and Eu2＋ ions were 5% and 4%, respectively. The chromaticity coordinates can be adjusted by the change of the concentration of Ce3＋ and Eu2＋ ions. Ba2Ca（BO3）2： Ce3＋, Eu2＋, Na＋ is a promising tunable two-color phosphor for white LED with near ultraviolet chip.