Dy~(3+)激活的LiSrBO_3材料光谱特性研究

研究了Dy~(3+)激活的LiSrBO_3材料的光谱特性。材料的发射光谱为一多峰宽谱,主峰分别为486,578和668 nm;监测578 nm发射峰时所得材料的激发光谱为一多峰宽谱,主峰分别为331,368,397,433,462和478 nm。研究了Dy~(3+)掺杂浓度对材料发射光谱的影响,结果显示,随Dy~(3+)浓度的增大,黄、蓝发射峰强度比(Y/B)逐渐增大;同时材料的发光强度随Dy~(3+)浓度的增大呈现先增大后减小的趋势,在Dy~(3+)浓度为3 mol%时到达峰值,其浓度猝灭机理为电偶极·偶极相互作用。引入Li~+,Na~+和K~+均可提高材料的发射强度。

Study of Spectra Characteristics of Dy~(3+) -Activated LiSrBO_3 Phosphor

The LiSrBO_3;Dy~(3+)phosphor was synthesized by solid-state method. SrCO_3 (99. 9%), Li_2CO_3 (99. 9%), H_3BO_3 (99. 9%) and Dy~(3+) (99. 9%) were used as starting materials. After these individual materials were blended and grounded thoroughly in an agate mortar, the homogeneous mixture was heated at 700 ℃ for 2 h in air, and LiSrO_3 : Dy~_(3+)phosphors were obtained. The phase present of the samples was characterized by powder X-ray diffraction (XRD) (D/max-rA, Cu K_α 40 kV, 40 mA,λ=0.154 06nm). The excitation and emission spectra of these phosphors were measured by a RF-540 photolumines-cence spectrophotometer. The emission spectrum of LiSrBO_3 : Dy~(3+) phosphor shows several bands at 486, 578 and 668 nm, respectively. The excitation spectrum for 578 nm emission has several excitation bands at 331, 368, 397, 433, 462 and 478 nm, respectively. The effect of Dy~(3+) concentration on the emission intensity of LiSrBO_3 : Dy~(3+) was investigated, and the result shows that the emission intensity of LiSrBO_3 : Dy~(3+) phosphor firstly increases with increasing Dy~(3+) concentration, then decreases, viz. the concentration quenching exists. And the Dy~(3+) concentration corresponding to the maximal emission intensity is 3 mol%, and the concentration quenching mechanisms are the d-d interaction by Dexter theory.