稀土掺杂Gd_(2)Te_(4)O_(11)亚碲酸盐荧光粉的合成及其发光性能

采用水热法制备了一系列稀土Dy^(3+),Tb^(3+),Eu^(3+)掺杂的极性Gd_(2)Te_(4)O_(11)(GTO)亚碲酸盐荧光粉.对样品的物相结构、形貌和热稳定性等进行了表征,测试了样品的发光性能.结果显示,所制样品均为单相,呈短杆状形貌,尺寸在微米量级,热稳定性能良好.对于GTO:Dy^(3+)荧光粉,在紫外光激发下的发光主要位于黄绿光区,获得最强发光强度的掺杂浓度为2.5%,色坐标为(0.39,0.43);荧光衰减曲线表明GTO:Dy^(3+)样品发光寿命随着掺杂浓度增大逐渐减小,与Dy^(3+)离子间的交叉弛豫有关.对于GTO:Eu^(3+)荧光粉,在紫外光激发下的发光主要位于红光和橙红光区,其发射强度随着Eu^(3+)掺杂浓度的增大而增强.当掺杂浓度为10%时,样品发光的色坐标为(0.62,0.38),位于橙红光区,且样品的发光寿命几乎不受掺杂浓度影响.对于GTO:Tb^(3+)荧光粉,随着Tb^(3+)掺杂浓度的增大,受Tb^(3+)离子间交叉弛豫的影响,荧光粉在紫外光激发下的发射从蓝紫区向黄绿光区转变;其中,当Tb^(3+)浓度为0.5%时,样品表现为白光发射,色坐标为(0.33,0.35),显色指数达86.变温荧光光谱测试结果显示,上述荧光粉具有良好的发光热稳定性.对三类荧光粉的内量子效率进行了测试,其中GTO:Eu^(3+)量子效率优于GTO:Dy^(3+)和GTO:Tb^(3+),各样品量子效率仍有较大提升空间.

Infrared-to-green upconversion properties of Er^(3+)/Yb^(3+) co-doped TeO_2-TiO_2-K_2O glasses upon excitation with 976 nm lasers diode

The energy transfer and upconversion of Er 3+ /Yb 3+ co-doped TeO2-TiO2-K2O glasses upon excitation with 976nm lasers diode were studied. The tellurite glasses were prepared by conventional melting methods. Their optical properties and sensitization upconversion spectra were performed. The dependence of green upconversion luminescence intensity on the mole ratio of Yb 3+ to Er 3+ and Er 3+ concentration were discussed in detail. When the mole ratio of Yb 3+ to Er 3+ is 25/1 and Er 3+ concentration is 0.1% （mole fraction）, or when the mole ratio of Yb 3+ to Er 3+ is 10/1 and Er 3+ concentration is 0.15%, the optimal upconversion luminescence intensity is obtained. The obtained glasses can be one of the potential candidates for lasers-diode pumping microchip solid-state lasers.