采用传统高温固相法合成了一个系列不同Er3+浓度单掺的BaGd2ZnO5荧光粉和两个系列分别改变Er3+、Yb3+浓度的共掺杂BaGd2ZnO5荧光粉.采用X射线衍射对得到荧光粉的晶体结构进行了分析,证实所有产物均为纯相BaGd2ZnO5,掺杂浓度的变化未引起晶相改变.采用980 nm激光作为激发源,在同样条件下测量了不同稀土掺杂浓度样品的上转换发射光谱.实验发现Er3+单掺杂样品的绿色上转换发光强于红色上转换发光;当Yb3+浓度为20%,不同Er3+浓度共掺杂样品的红色上转换发光强于绿色发射上转换发射;而固定Er3+浓度为5%,不同Yb3+浓度样品的红色和绿色上转换发射强度均较强.研究了不同稀土离子掺杂浓度样品的上转换发光强度与激光器工作电流(即不同激发功率密度)的关系,通过分析发现所有样品的红色和绿色上转换发光均为双光子过程.计算了不同稀土掺杂浓度样品的色坐标,发现掺杂浓度对样品色坐标具有较大影响,通过调整掺杂浓度可对色坐标进行调整.

Er3+ single doped BaGd2ZnO5 phosphors with various Er3+ concentrations,Er3+/Yb3+ codoped BaGd2ZnO5 phosphors with various concentrations of Er3+ or Yb3+ were obtained via a traditional high temperature solid state method.Crystal structure of the obtained phosphors was characterized by means of X-Ray Diffraction,and it was confirmed that all products exhibited pure phase as BaGd2ZnO5,and that the doping concentration did not evoke change in crystal structure.The upconversion emission spectra for all samples with different rare earth ion concentrations were measured upon 980 nm excitation under the same experimental conditions.It was observed that the green upconversion intensity was larger than that of the red one in the Er3+ single doped phosphors,the red upconversion intensity was larger than that of the green one in the samples with fixed Yb3+ concentration of 20% and various Er3+ concentrations,moreover,the both green and red upconversion intensities are higher for the samples with fixed Er3+ concentration of 5% and various Yb3+ concentrations.The dependence of upconversion intensity on the laser working current (the different excitation power densities) was analyzed,and the two-photon process was confirmed to be responsible for the green and red emissions.The color coordinates for all the samples were calculated,and it is seen that the doping concentration greatly influenced the color coordinates which can be tuned by the rare earth ion doping concentration.