【摘要】 从能量传递的角度出发,利用同步辐射光源(德国HASYLAB实验室的SUPERLUM I实验站)对Pr3+和Mn2+掺杂的SrB4O7粉末样品进行了光谱研究。206 nm激发下,在SrB4O7∶Pr3+(0.1%,摩尔分数)样品中观察到了来自Pr3+离子1S0能级的光子级联发射。SrB4O7∶Pr3+样品的发射谱与SrB4O7∶Mn2+样品监测Mn2+离子640 nm发射的激发谱在330~430 nm的波长范围里存在显著的光谱重叠。这个光谱重叠有利于Pr3+→Mn2+的能量传递发生,从而将Pr3+离子级联发射中第一步不实用的紫外或近紫外光子转换为Mn2+的红光发射。双掺杂样品SrB4O7∶Pr3+,Mn2+与单掺杂样品SrB4O7∶Pr3+的发射谱比较揭示出Pr3+→Mn2+的能量传递的确存在,并且提供了一种传递效率的估算方法,表明通过“Pr3+-Mn2+”组合有可能获得量子效率大于1的高效真空紫外激发发光材料。更多还原

【Abstract】 The luminescence of Pr³⁺ or Mn²⁺ singly doped as well as Pr³⁺ and Mn²⁺ codoped SrB₄O₇ powder microcrystalline samples were investigated using synchrotron radiation.The photon cascade emission origi-（nating） from the ¹S₀ level was observed in the SrB₄O₇∶Pr³⁺（0.1%,mol fraction） sample upon 206 nm excitation.There are desirable spectral overlaps in the region of 330⁴30 nm between the emission spectra of the SrB₄O₇∶Pr³⁺ sample and the excitation spectra of the SrB₄O₇∶Mn²⁺ sample monitoring the Mn²⁺ luminescence at 640 nm.The wavelengths corresponding to transitions ¹S₀→¹I₆,³P_2,1,0（405 nm） and ¹S₀→¹D₂（340 nm） of Pr³⁺ coincide very well with those corresponding to transitions ⁶A_1g→⁴E_g-⁴A_1g（410 nm） and ⁶A_1g→⁴T_2g（350 nm） of Mn²⁺,respectively.These spectral overlaps are in favor of the energy transfer from Pr³⁺ to Mn²⁺,converting the first step photon from Pr³⁺:¹S₀ in the unpractical ultraviolet or near-ultraviolet regions into the red Mn²⁺ emission.A comparison of the room temperature emission spectra of the SrB₄O₇∶Pr³⁺,Mn²⁺ sample with that of the SrB₄O₇∶Pr³⁺ sample revealed the existence of the proposed energy transfer between Pr³⁺ and Mn²⁺.This conclusion about Pr→Mn energy transfer was also supported by the evidences from the low temperature（10 K） spectra and decay curves of 405 nm emission from Pr³⁺ singly doped and Pr³⁺,Mn²⁺ codoped samples.The efficiency of the energy transfer was estimated to be 43% by a simple equation based on the comparison of the emission spectra of the SrB₄O₇∶Pr³⁺,Mn²⁺ sample with that of the SrB₄O₇∶Pr³⁺ sample,thus a 143% quantum efficiency was achieved,suggesting an promising VUV phosphor based on Pr³⁺ and Mn²⁺ combination.更多还原