Yb^(3＋)、Ho^(3＋)掺杂浓度及晶粒尺寸对NaYF_4∶Yb^(3＋),Ho^(3＋)上转换材料发光的影响

The influences of Yb^(3+) and Ho^(3+) doping concentration and grain size on the luminescence properties of NaYF_4∶Yb^(3+),Ho^(3+) upconversion materials

EDTA作为络合剂,在pH值为5的条件下,采用水热法制备了NaYF4∶Yb3+,Ho3+微米棱柱上转换材料,研究了掺杂浓度和晶粒尺寸对上转换发光特性的影响。实验发现材料发光主要以绿光为主,最佳的Yb3+、Ho3+掺杂浓度分别为25%和1%,高于此值均会出现浓度猝灭效应。通过改变溶液中NaF/NH4HF2摩尔比来调控晶粒的尺寸,发现随着晶体颗粒尺寸的增大,材料中Yb3+浓度增加,从而使上转换发光增强。

Up-conversion（UC） material NaYF4 micron prisms were synthesized by hydrothermal method.The influences of Yb3＋ and Ho3＋ doping concentration and grain size on the luminescence properties of NaYF4 was studied detailedly.It was found that the emission was dominated by green light due to the low phonon energy,and the optimum doping concentrations for Yb3＋ and Ho3＋ were 25% and 1%,respectively,and higher Yb3＋ and Ho3＋ concentrations will cause the concentration quenching effect.The grain size increases with the decrease of NaF/NH4HF2 ratios in solution,leading to the increase of UC emission.