基于变温变激发的YVO_(4):1%Er^(3+)的荧光温度特性

Temperature Related Fluorescence Characteristics of YVO_(4):1%Er^(3+)Based on Variable Excitation

本文研究了不同波长激发下YVO_(4):1%Er^(3+)的荧光测温特性。在312和345 nm照射下,测量了YVO_(4):1%Er^(3+)的变温激发光谱和发射光谱。结果表明,在303~573 K范围内,随着温度的增加,在312 nm激发下,Er^(3+)离子的^(2)H_(11/2)→^(4)I_(15/2)发射增强,^(2)S_(3/2)→^(4)I_(15/2)发射减弱;在345 nm激发下,Er^(3+)离子的^(2)H_(11/2)→^(4)I_(15/2)发射增强,^(2)S_(3/2)→^(4)I_(15/2)发射也增强。我们认为在312 nm激发下,随温度的变化,Er^(3+)的^(2)H_(11/2)→^(4)I_(15/2)发射增强和^(2)S_(3/2)→^(4)I_(15/2)发射减弱来源于稀土离子热布居效应和基质的吸收减弱;在345 nm激发下,Er^(3+)的^(2)H_(11/2)→^(4)I_(15/2)发射和^(2)S_(3/2)→^(4)I_(15/2)发射同时增强来源于基质和稀土离子的基态热布居效应。通过拟合^(2)H_(11/2)和^(2)S_(3/2)两个能级的能级差,得到△E_(312)=650.94 cm^(-1),△E_(345)=674.36 cm^(-1),这样的结果也说明不同的激发可以实现相反的荧光强度变化趋势,但并不影响两能级间粒子数的玻尔兹曼分布。

The fluorescence temperature sensing characteristics of YVO4:1%Er^(3+)excited under different wavelengths have been investigated.The variable-temperature excitation and emission spectra of YVO_(4):1%Er^(3+)were measured excited at 312 and 345 nm.The results indicate that,in the temperature range of 303-573 K,an increase in temperature leads to an enhancement of the Er^(3+)ion′s^(2)H_(11/2)to^(4)I_(15/2)emission and a weakening of the^(2)S_(3/2) to^(4)I_(15/2)emission under 312 nm excitation.Conversely,under 345 nm excitation,both the^(2)H_(11/2)to^(4)I_(15/2)and the^(2)S_(3/2)to^(4)I_(15/2)emissions are enhanced.It is postulated that the observed changes in emission under 312 nm excitation with temperature are due to the thermal population effect of the rare-earth ions and the reduced absorption by the matrix;while under 345 nm excitation,the simultaneous enhancement of both emissions is attributed to the thermal population effects of the matrix and the ground state of the rare-earth ions.By fitting the energy level difference between the^(2)H_(11/2)and^(2)S_(3/2)levels,the values of △E_(312)=650.94 cm-1 and △E_(345)=674.36 cm^(-1)are obtained.These results also demonstrate that different excitation wavelengths can lead to opposite trends in fluorescence intensity changes,yet do not affect the Boltzmann distribution of particle numbers between the thermally coupled energy levels.