Y3+掺杂对CaGdAlO4:Pr3+,Yb3+荧光粉的微结构及其量子剪裁发光的影响

采用自蔓延燃烧法结合后期热处理手段制备得到了Y3+/Pr3+共掺杂的CaGdAlO4荧光粉材料.实验结果表明:当用与Gd3+离子半径较近的Y3+来取代Gd3+时,Pr3+的光致发光强度增强,使来自Pr3+的4f-5d跃迁的吸收峰峰值位置发生了从261nm至259nm的蓝移.在确定Y3+的最优浓度为50%,Pr3+的最优浓度为0.5%时,进一步制备了Y3+/Pr3+/Yb3+共掺杂的CaGdAlO4荧光粉材料,并实现了从深紫外到近红外的量子剪裁.在Yb3+的浓度达到6%时,Yb3+位于980nm的发射峰最强.经计算Y3+/Pr3+/Yb3+共掺杂的CaGdAlO4材料的量子剪裁效率约为168%,优于Pr3+/Yb3+共掺杂的CaGdAlO4荧光粉.此外,在254nm紫外光照射下,Y3+取代Gd3+的策略在一定程度上抑制了CaGdAlO4荧光粉材料的晶格热化现象.综上,用价格更低的Y部分取代Gd,可使CaGdAlO4:Pr3+/Yb3+荧光粉制备成本降低,并进一步优化其量子剪裁性能.该研究对硅空间太阳能电池的应用开发具有实际意义.

Effects of Y3+ Doping on the Microstructure and Quantum Cutting Luminescence of CaGdAlO4:Pr3+,Yb3+ Phosphors

Y3+/Pr3+co-doped CaGdAlO4 phosphors were prepared by a self-propagating combustion method in combination with a subsequent heat treatment.The experimental results show that,when Gd3+is replaced by Y3+,whose ion radius is close to that of Gd3+,the enhanced luminescence intensity of Pr3+leads to a blue-shift of the maximum position of the absorption peak originating from the 4 f-5 d transition of Pr3+from 261 nm to 259 nm.When the optimal concentrations of Y3+and Pr3+were determined to be 50% and 0.5%,respectively,Y3+/Pr3+/Yb3+co-doped CaGdAlO4 phosphors were further prepared,and their quantum cutting luminescence from deep ultraviolet to near-infrared was realized.As the Yb3+concentration reaches to 6%,the strongest luminescence of Yb3+at 980 nm was observed.It is found that the calculated quantum cutting efficiency of Y3+/Pr3+/Yb3+co-doped CaGdAlO4 phosphors is about 168%,which is higher than that of Pr3+/Yb3+co-doped CaGdAlO4 phosphors.Moreover,under ultraviolet light(254 nm)irradiation,the strategy of substituting Y for Gd in the CaGdAlO4 host can inhibit the lattice thermalization in a certain extent.In a word,the replacement of Gd by cheap Y can lead to the reduced cost of the phosphors and the improved quantum cutting performance.This study has practical significance for developing and applying silicon space solar cells.