应用于白光显示的Tm^(3+)/Ho^(3+)/Yb^(3+)共掺碲酸盐玻璃上转换发光特性研究

Upconversion luminescence of Tm^(3+)/Ho^(3+)/Yb^(3+) codoped tellurite glass used for white light emission

用高温熔融法制备了Tm3+/Ho3+/Yb3+共掺碲酸盐玻璃(TeO2-ZnO-La2O3)样品,测试了玻璃样品的吸收光谱和上转换发光光谱,分析了上转换发光机理.结果发现:在975nm波长激光二极管(LD)激励下,制备的碲酸盐玻璃样品可以观察到强烈的红光(662nm)、绿光(546nm)和蓝光(480nm)三基色上转换发光,红光对应于Tm3+离子1G4→3F4和Ho3+离子5F5→5I8,绿光对应于Ho3+离子5S2(5F4)→5I8,蓝光对应于Tm3+离子1G4→3H6的能级跃迁.随着Yb3+离子掺杂含量和抽运功率的增加,样品的上转换发光强度得到了一定程度的提高.通过调整稀土掺杂的浓度得到了接近于标准的白光发射.研究结果对于探索实现高品质的白光发光二极管(LED)具有实际应用意义.

Tm3＋/Ho3＋/Yb3＋ codoped tellurite glass （TeO2 -ZnO-La2 O3） was prepared by conventional melt-quenching method. The absorption spectra and upconversion spectra of the glass were measured, and the upconversion luminescence mechanism was analyzed. Intensive red （662 nm）,green （546 nm） and blue （480 nm） emissions of the tellurite glass were simultaneously observed at room temperature under 975 nm LD excitation. Upconversion red luminescence are due to the energy transition of Tm3 ＋ ion： 1 G4 →3 F4 and Ho3 ＋ ion： 5 F5 →5 I8 ,while upconversion green and blue are the results of Ho3 ＋ ion： 5 S2 →5 I8 and Tm3 ＋ ion： 5 S2 （5 F4） →5 I8 ,respectively. With the increasing of Yb3 ＋ content and the pump power,upconversion luminescence are also enhanced. The white light close to the standard white light emission has been obtained by adjusting the concentration of rare earth doping. Our result has practical significance for developing high-quality white LED.