太阳电池用YVO_4∶Eu~(3+)下转换材料的掺杂改性研究

为进一步提高YVO_4材料的下转换发光性能,在改进后的溶胶-凝胶法制备的YVO_4∶Eu~(3+)中,通过掺入Bi~(3+)来拓宽其在紫外波段的光谱吸收并提高其发光强度,通过掺入P~(5+)达到以PO_4~(3-)部分取代VO_4~(3-)来改善YVO_4∶Eu~(3+)的光输出稳定性及温度猝灭特性的目的。研究表明,掺入的Bi~(3+)和P~(5+)可成功取代YVO_4晶格中的Y~(3+)和V~(5+)。当Bi~(3+)掺入量较少时,样品仍然为四方晶系,Bi~(3+)较好地取代了Y~(3+)的晶格位置,形成单相的晶体结构。而在掺入少量的P~(5+)之后,YVO_4与YPO_4之间形成了均匀的固溶体。在350 nm激发光源作用下,当Bi~(3+)和P5+掺杂摩尔分数分别为0.04和0.10时,发光强度达到最大,特别是YV0.90P0.10O4∶0.05Eu~(3+)在619 nm处的发光强度要比YVO_4∶0.05Eu~(3+)的发光强度增大1.9倍。

Doping Modification of YVO4:Eu3+ Down-conversion Materials for Solar Cell Applications

Bismuth ( Bi3+) and phosphorus ( P3+) ions doped YVO4:Eu3+ down-conversion materi-als were prepared by modified sol-gel method to broaden the absorption range of ultraviolet light and enhance the stability of light emission. It is shown that some positions of Yttrium ( Y3+) and Vana-dium ( V5+) ions can be successfully replaced by incorporated Bismuth ( Bi3+) and phosphorus ( P3+) ions in the YVO4 lattice. As to low Bi3+ doping, the crystal structure is still tetragonal and the position of Y3+ is well substituted by Bi3+. While for low P3+ doping, a homogeneous solid solu-tion is formed between YVO4 and YPO4 . Under the excitation of 325 nm, the highest luminescence intensity can be obtained with Bi3+ mole fraction of 0. 04 and P5+ mole fraction of 0. 10, respective-ly. In that case, the instensity of YV0. 90 P0. 10 O4:0. 05Eu3+ can increase up to 1. 9 times comparing to YVO4:0. 05Eu3+.