Yb^(3+)/Ho^(3+)共掺杂Sc^(2)W_(3)O_(12)荧光粉的上转换发光和温度传感特性

Upconversion Luminescence and Temperature Sensing Properties of Yb^(3+)/Ho^(3+) Co-Doped Sc^(2)W_(3)O_(12) Phosphors

利用水热法结合煅烧制备Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+荧光粉,用X射线衍射仪、扫描电子显微镜和荧光光谱仪对样品进行表征。在980 nm的激光激发下,Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+表现出了542、657和752 nm三个特征峰,分别对应于Ho^(3+)的^(5)F_(4)/^(5)S_(2)-^(5)I_(8),^(5)F_(5)-^(5)I_(8) 和 ^(5)F_( 4)/^(5)S_( 2)-^(5)I_(7)能级跃迁,分别发射出绿光、红光和弱红光。讨论了荧光粉的上转换发光机理,得出绿色和红色上转换发射均为双光子过程。基于荧光强度比技术,在323~523 K温度范围内研究了^(5)F_(4)/^(5)S_(2)与^(5)F_(5)这对非热耦合能级的上转换发光强度与温度的关系,得出在523 K时荧光粉的最大绝对灵敏度达到1%K-1,结果表明Sc^(2)W_(3)O_(12):Yb ^(3+)/Ho^( 3+)荧光粉可以作为温度传感器的候选材料。

Sc^(2)W_(3)O_(12):Yb^(3+)/Ho^(3+)phosphor was prepared by hydrothermal method combined with calcination.The samples were characterized by X-ray diffractometer,scanning electron microscope and fluorescence spectrometer.Under 980 nm laser excitation,Sc^(2)W_(3)O_(12):Yb^(3+)/Ho^(3+)showed three characteristic peaks at 542,657 and 752 nm,corresponding to the ^(5)F_(4)/^(5)S_(2)-^(5)I_(8),^(5)F_(5)-^(5)I_(8) and ^(5)F_( 4)/^(5)S_( 2)-^(5)I_(7) energy level transitions of Ho 3+,respectively,emitting green,red and weak red light.The upconversion luminescence mechanism of the phosphor was discussed,and it was concluded that the green and red upconversion emissions are two-photon processes.Based on the fluorescence intensity ratio technique,the relationship between the upconversion luminescence intensity and temperature of the non-thermally coupled energy levels of 5F 4/5S 2 and 5F 5 was studied in the temperature range of 323~523 K.The maximum absolute sensitivity of the phosphor reached 1%K-1 at 523 K.The results show that Sc^(2)W_(3)O_(12):Yb^(3+)/Ho^(3+)phosphor can be used as a candidate material for temperature sensors.