YP_(1-x)V_xO_4∶Eu^(3+)在真空紫外区发光的优化

Luminescence Optimization of YP_(1-x)V_xO_4∶Eu^(3+) under VUV Excitation

系统地考查了Eu3 + 在YPO4 YVO4 固溶体中的发光。当V5+ 的浓度低于 0 3 ,出现VO4 3 -离子团的蓝色发射 ;直到V5+ 的浓度等于或大于 0 3时 ,VO4 3 -离子团的蓝色发射才被Eu3 + 离子的红色发射所猝灭 ,发射主波长在 61 9nm。在真空紫外线的激发下 ,Eu3 + 在YPO4 YVO4 固溶体有较强发光 ,并随着P5+ 浓度的增加 ,Eu3 + 离子的发光增强。经过优化的组成为YP0 7V0 3 O4 ∶Eu3 + 的荧光粉在真空紫外激发下既具有较强的发光 ,又具有优良的色纯度 ,将是一种新型的良好的等离子体平板显示用荧光粉。

The search for new high efficient phosphors is of great importance for plasma display panel (PDP) as the rapid development of this new technology. The PDP red phosphor used is still insufficient to meet the demand of full color PDP because of the low color saturation. New red phosphor with high color saturation and high luminescent efficiency is urgently needed. YP 1- x V x O 4:Eu 3+ , with good color saturation (main emission at 619nm), is well known as a high efficient red phosphor under UV excitation. In this paper, YP 1- x V x O 4∶Eu 3+ was prepared carefully at high temperature in solid state reaction. The luminescence of YP 1- x V x O 4∶Eu 3+ was studied under VUV/VU excitation. YP 1- x V x O 4∶Eu 3+ was identified as forming solid solution based on the Vegard′s rule. The strongest emission in YPO 4:Eu 3+ was observed at 593nm and in YP 1- x V x O 4∶Eu 3+ (0 2≤ x ≤1) at 619nm. Additionally, the blue emission from VO 4 3- , except the red emission of Eu 3+ , can be observed when the V 5+ concentration is lower than 0 3. This blue emission will be quenched by Eu 3+ emission when the V 5+ concentration equal to or larger than 0 3. In the UV excitation spectra of YP 1- x V x O 4∶Eu 3+ (0 2≤ x ≤1), the absorption band of (P 1- x V x )O 4 3- and Eu 3+ charge transfer band were observed overlapping at UV region and shift to a longer wavelength with increasing V 5+ concentration. In the VUV excitation spectra of YP 1- x V x O 4∶Eu 3+ ,a very narrow band was observed locating at 153nm in YPO 4∶Eu 3+ while a broad band in the same region were observed in other systems with varying x value. The narrow band is assumed to the absorption of PO 4 3- while these broad bands are to P 1- x V x O 4 3- anion. Moreover, a band around 200 nm was also observed similar to the absorption of Y 2O 3, which is attributed to Y O absorption. The luminescence efficiency of YP 1- x V x O 4∶Eu 3+ (0 2≤ x ≤1) increases with the increasing of P 5+ concentration, consistent with the increasing ionic character of P 1- x V x O 4 3- anion. This seems to imply that host with stronger ionic character is more favorable for host sensitization on activator. An optimized constituent,YP 0 7 V 0 3 O 4∶Eu 3+ , which has 30% higher luminescent intensity than that of commercial Y 2O 3∶Eu for PDP under 147nm excitation and 12 5% higher under 172nm excitation and a better red color saturation, will be a new potential red phosphor for plasma display panel (PDP).