Ce~(3+)、Tb~(3+)在SrZnP_2O_7材料中的发光及能量传递

采用高温固相法制备了Ce3+、Tb3+激活的SrZnP2O7材料,并研究了材料的发光性质。在290 nm紫外光激发下,SrZnP2O7∶Ce3+材料的发射光谱为双峰宽谱,主峰位于329 nm。SrZnP2O7∶Tb3+材料的发射光谱由420,443,491,545,587,625 nm六个峰组成,分别对应Tb3+的5D3→7F5、5D3→7F4、5D4→7F6、5D4→7F5、5D4→7F4和5D4→7F3特征发射;监测545 nm最强发射峰,所得激发光谱覆盖200~400 nm,主峰为380 nm。研究了Ce3+、Tb3+在SrZnP2O7材料中的能量传递过程,发现,Ce3+对Tb3+具有很强的敏化作用,提高了SrZnP2O7∶Tb3+材料的发射强度,当Ce3+摩尔分数为3%时,SrZnP2O7∶Tb3+材料的发射强度提高了近2倍。引入电荷补偿剂可提高SrZnP2O7∶Tb3+材料的发射强度,其中以掺入Li+和Cl-时效果最明显。

Luminescence and Energy Transfer between Ce~(3+) and Tb~(3+) in SrZnP_2O_7 Phosphor

SrZnP2O7 ∶ Tb3+, SrZnP2O7 ∶ Ce3+ and SrZnP2O7 ∶ Ce3+,Tb3+ phosphors were prepared by solid state reaction, and their luminescent characteristics were investigated. SrCO3(A.R.), ZnO(A.R.), NH4H2PO4(A.R.), Li2CO3(A.R.), Na2CO3(A.R.), K2CO3(A.R.), NH4Cl(A.R.), Tb4O7(99.99%) and CeO2(99.99%) were used as starting materials, after these individual materials ground thoroughly in an agate mortar, the homogeneous mixture was heated at 900 ℃ for 3 h in reduce atmosphere, and these phosphors were obtained. The phase presents of the samples were characterized by powder X-ray diffraction (XRD) (D/max-rA, Cu Kα, 40 kV, 40 mA, λ=0.154 06 nm). The excitation and emission spectra of these phosphors were measured by a SHIMADZU RF-540 fluorescence spectrophotometer. SrZnP2O7 ∶ Ce3+ shows a broad band at 329 nm. SrZnP2O7 ∶ Tb3+ has six emission peaks at 420, 443, 491, 545, 587 and 625 nm which correspond to the 5D3→7F5, 5D3→7F4, 5D4→7F6, 5D4→7F5, 5D4→7F4 and 5D4→7F3 characteristic transitions of Tb3+ , respectively, at 380 nm excitation. Monitoring 545 nm peak, the excitation spectrum extends from 200 nm to 400 nm, and the peak locates at 380 nm. Energy transfer from Ce3+ to Tb3+ in SrZnP2O7 ∶ Ce3+,Tb3+ phosphor was investigated, and the emission intensity of SrZnP2O7 ∶ Tb3+ can be enhanced by energy transfer from Ce3+ to Tb3+. Under the conditions of charge compensator Li+, Na+, K+ or Cl- incorporated in SrZnP2O7 ∶ Tb3+ phosphor, the emission intensities of the phosphor are enhanced, too.