Zhang Zhiyu, Guo Chongfeng, Suo Hao, Zhao Xiaoqi, Zhang Niumiao, Li Ting
National Key Laboratory of Photoelectric Technology, Functional Materials (Culture Base) in Shaanxi Province, National Photoelectric Technology, Functional Materials & Application of Science and Technology International Cooperation Base, Institute of Photonics & Photon-Technology, Northwest University, Xi'an, 710069, China.
Phys Chem Chem Phys. 2016 Jul 28;18(28):18828-34. doi: 10.1039/c6cp02746f. Epub 2016 Jun 27.
Yb(3+)/Er(3+)-ion co-doped Na2Ln2Ti3O10 (Ln = Gd, La) up-conversion (UC) phosphors were successfully synthesized by a sol-gel method, and their crystal structures were characterized by powder X-ray diffraction. Dazzling yellow-greenish light was emitted under the excitation of 980 nm near-infrared (NIR) light, composing green and red emission bands from the (2)H11/2/(4)S3/2→(4)I15/2 and (4)F9/2→(4)I15/2 transitions of Er(3+), respectively. The optimal composition and synthesis parameters were determined according to their UC emission intensity. The photon absorption and emission processes were illustrated based on the UC mechanism, in which energy transfer (ET) from Yb(3+) to Er(3+) plays a pivotal role and has been proved by the variation of green emission lifetime in Er(3+) singly and Yb(3+)/Er(3+) co-doped Na2Ln2Ti3O10 samples. The temperature-dependent fluorescence intensity ratios (FIR) of the two thermal coupled energy level (TCL) emission from (2)H11/2→(4)I15/2 (526 nm) and (4)S3/2→(4)I15/2 (549 nm) were calculated in the range of 290-490 K, and their sensitivity values were approximately 0.0058 K(-1) for Na2Gd2Ti3O10 at 490 K and 0.0061 K(-1) for Na2La2Ti3O10 at 470 K, as potential optical temperature sensor.
采用溶胶-凝胶法成功合成了Yb(3+)/Er(3+)共掺杂的Na2Ln2Ti3O10（Ln = Gd、La）上转换（UC）荧光粉，并用粉末X射线衍射对其晶体结构进行了表征。在980 nm近红外（NIR）光激发下发射出耀眼的黄绿色光，分别由Er(3+)的(2)H11/2/(4)S3/2→(4)I15/2和(4)F9/2→(4)I15/2跃迁组成绿色和红色发射带。根据其UC发射强度确定了最佳组成和合成参数。基于UC机制阐述了光子吸收和发射过程，其中Yb(3+)到Er(3+)的能量转移（ET）起关键作用，并且通过Er(3+)单掺杂和Yb(3+)/Er(3+)共掺杂的Na2Ln2Ti3O10样品中绿色发射寿命的变化得到了证实。计算了290 - 490 K范围内(2)H11/2→(4)I15/2（526 nm）和(4)S3/2→(4)I15/2（549 nm）两个热耦合能级（TCL）发射的温度依赖荧光强度比（FIR），作为潜在的光学温度传感器，其在490 K时Na2Gd2Ti3O10的灵敏度值约为0.0058 K(-1)，在470 K时Na2La2Ti3O10的灵敏度值约为0.0061 K(-1)。
