Color tuning of (K1-x, Nax)SrPO4:0.005Eu2+, yTb3+ blue-emitting phosphors via crystal field modulation and energy transfer
Color tuning of (K1-x, Nax)SrPO4:0.005Eu2+, yTb3+ blue-emitting phosphors via crystal field modulation and energy transfer
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DOI：
10.1039/c3tc30128a
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Wang, Xiaojun
中科院分区：
文献类型：
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作者：
Dai, Pengpeng;Zhang, Xintong;Wang, Xiaojun
通过高温固相反应合成了K1-xNaxSrPO4：0.005Eu(2+)和K0.4Na0.6Sr0.995-yPO4：0.005Eu(2+)，yTb(3+)两个系列的荧光粉。它们的发射颜色可以通过调节晶场强度和能量转移从深蓝调到蓝绿色。K+与Na+的部分取代导致了K1-xNaxSr0.995PO4：0.005Eu(2+)基质晶胞的收缩和扭曲，使发射从426 nm调谐到498 nm。红移发射是由于Eu2+在较低的对称性晶场中的晶场分裂增加所致。阴极发光光谱进一步证明了可调谐发射，这表明K1-xNaxSr0.995PO4：0.005Eu(2+)荧光粉的发光分布非常均匀。此外，利用能量传递原理，通过与Tb3+的共掺杂可以进一步调谐发光颜色。共掺荧光粉K0.4Na0.6Sr0.995-yPO4：0.005Eu(2+)，yTb(3+)的色度坐标可以从y=0的(0.202，0.406)调整到y=0.09时的(0.232，0.420)。研究了敏化剂Eu~(2+)向激活剂Tb~(3+)的能量传递过程，证明了能量传递过程具有共振型偶极-偶极相互作用机制，用浓度猝灭法计算出能量传递的临界距离为12.46埃。
Two series of K1-xNaxSrPO4:0.005Eu(2+) and K0.4Na0.6Sr0.995-yPO4:0.005Eu(2+), yTb(3+) phosphors are synthesized via a high-temperature solid-state reaction. Their emission color can be tuned from deep blue to blue-green by modulating the crystal field strength and energy transfer. Partial substitution of K+ with Na+ results in a contraction and distortion of the unit cell of the K1-xNaxSr0.995PO4:0.005Eu(2+) host, tuning the emission from 426 to 498 nm. The red-shifted emission is attributed to an increased crystal field splitting for Eu2+ in a lowered symmetry crystal field. The tunable emission is further demonstrated in the cathodoluminescence spectra, which indicates that the luminescence distribution of the K1-xNaxSr0.995PO4:0.005Eu(2+) phosphor is very homogenous. Additionally, utilizing the principle of energy transfer, the emission color can be further tuned by co-doping with Tb3+. The chromaticity coordinates for the co-doped phosphor, K0.4Na0.6Sr0.995-yPO4:0.005Eu(2+), yTb(3+), can be adjusted from (0.202, 0.406) for y = 0 to (0.232, 0.420) for y = 0.09. The energy transfer processes from the sensitizer (Eu2+) to the activator (Tb3+) are studied and demonstrated to have a resonance-type dipole-dipole interaction mechanism, with the critical distance of the energy transfer calculated to be 12.46 angstrom using a concentration quenching method.