【摘要】 采用固相法成功制备了Ba₅Zn₄Y₈O₂∶Er³⁺,Yb³⁺上转换发光粉。X射线衍射（XRD）和扫描电镜（SEM）测试结果表明,发光粉结晶良好,平均粒径1⁵μm,呈碎颗粒状。在980nm激光器激发下,肉眼可见极其明亮的橙色发光。光谱测试结果证实,发光粉发射峰位于520⁵30,530⁵50和650⁶90nm间。其中,绿光发射源于Yb³⁺→Er³⁺两步能量传递对2H11/2、4S3/2能级的粒子布居,及随后向基态的跃迁。红光发射则主要与⁴I_11/2(Er³⁺)+⁴F_7/2(Er³⁺)→⁴F_9/2(Er³⁺)+⁴F_9/2(Er³⁺)交叉弛豫和⁴S_3/2(Er³⁺)+²F_7/2(Yb³⁺)→⁴I_13/2(Er³⁺)+²F_5/2(Yb³⁺)能量反传递、⁴I_13/2→⁴F_9/2激发态吸收及⁴F_9/2→⁴I_15/2跃迁有关。由于交叉弛豫和能量反传递可有效提高红光强度并削弱绿光发射,因此红光发射强度可达到绿光强度的6¹3倍。在7%（摩尔分数）的Yb³⁺掺杂条件下,Er³⁺的最佳掺杂浓度为3%（摩尔分数）。提高激发光功率密度不仅可以使UCL增强,还可以进一步提高红绿光分支比。在高功率激发下,还观察到了三光子吸收产生的蓝光和蓝绿光发射。更多还原

【Abstract】 A novel Ba₅Zn₄Y₈O₂₁∶Er³⁺,Yb³⁺upconversion phosphor has been synthesized by solid phase method.XRD and SEM measurement results show that the phosphor crystalized well and presented granular appearance with average particle size of 1-5μm.Under the excitation of 980 nm laser,extremely bright orange luminescence can be observed.Spectral test results confirm that the emission peaks are located in 520-530 nm,530-550 nm and 650-690 nm.The green emissions originate from the populations of ²H_11/2 and ⁴S_3/2 energy levels,and the subsequent transitions to the ground state.The red emission is mainly related to the cross relaxation of ⁴I_11/2(Er³⁺)+⁴F_7/2(Er³⁺)→⁴F_9/2(Er³⁺)+⁴F_9/2(Er³⁺)and the reverse energy transfer of ⁴S_3/2(Er³⁺)+²F_7/2(Yb³⁺)→⁴I_13/2(Er³⁺)+²F_5/2(Yb³⁺),as well as the transitions of ⁴I_13/2→⁴F_9/2 and ⁴F_9/2→⁴I_15/2.Due to the cross relaxation and reverse energy transfer,the red emission intensity can be effectively improved and the green emission can be reduced,so that the red emission intensity can reach 6-13 times of the green emission intensity.The best doping concentration of Er³⁺was 3mol% under the condition of 7mol% Yb³⁺doping content.Improving the power density of excitation light can not only enhance the UCL,but also improve the intensity ratio of red and green light.Under high power excitation,the blue and blue-green emissions caused by three photon absorption can also be observed.更多还原