Ho^(3+)、Yb^(3+)掺杂锡酸钙陶瓷的双模发光及光强调制研究

Dual-mode luminescence and light intensity modulation of Ho^(3+) and Yb^(3+) doped calcium stannate ceramics

稀土离子掺杂的无机光致变色材料通过将光致变色与光致发光强度调制进行耦合可应用于光信息存储。采用多光子吸收策略研制具有双模发光调制性能的材料,是提升光信息储存寿命的有效手段。本研究以锡酸钙为基体,选用Ho^(3+)和Yb^(3+)共掺杂,制备得到具有双模发光及光强调制特性的陶瓷。461 nm蓝光激发下,陶瓷在可见光区域产生强烈的绿色和红色发射。980 nm近红外光激发下,陶瓷出现3个以551、669和756 nm为中心的可见光发射带。对上转换发光机理展开讨论,结果表明陶瓷上转换发光与双光子过程相关。365 nmUV光照射使陶瓷上转换和下转换发光强度产生衰减调制现象,绿色发光调制效果优于红色。通过热释光光谱测试得到陶瓷内部的陷阱分布与深度信息,证明了载流子陷阱的存在。UV光照前后的荧光寿命测试和发光动力学测试结果表明,光强衰减与发光中心到陷阱中心的能量传递有关。

Rare earth ion-doped inorganic photochromic materials can be applied in the field of optical information storage by coupling photochromism with photoluminescence intensity modulation.The development of materials with dual-mode luminescence modulation properties using a multiphoton absorption strategy is an effective means to enhance the lifetime of optical information storage.In this study,ceramics with dual-mode luminescence and light intensity modulation properties were prepared by selecting Ho^(3+)and Yb^(3+)co-doping with calcium stannate as the host.The ceramic produces intense green and red emission in the visible region under 461 nm blue light excitation.Under the excitation of 980 nm near-infrared light,the ceramics appear three visible emission bands centered at 551 nm,669 nm and 756 nm.The mechanism of up-conversion luminescence is discussed,and the results show that ceramic up-conversion luminescence is related to the two-photon process.365 nm UV light irradiation of ceramic up-conversion and down-conversion luminescence intensity of attenuation modulation phenomenon,the green luminescence modulation effect is better than the red.Information on the distribution and depth of traps inside the ceramics was obtained by thermoluminescence spectroscopy tests,proving the existence of carrier traps.The results of fluorescence lifetime tests and luminescence kinetics tests before and after UV irradiation showed that the light intensity decay was related to the energy transfer from the luminescence center to the trap center.