Analogy of different optical temperature sensing techniques in LaNbO4: Er3+/Yb3+ phosphor
Analogy of different optical temperature sensing techniques in LaNbO4: Er3+/Yb3+ phosphor
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DOI：
10.1016/j.jlumin.2021.117992
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发表时间：
2021-04-01
影响因子：
3.6
通讯作者：
Sombra, A. S. B.
中科院分区：
文献类型：
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作者：
Pavani, K.;do Nascimento, J. P. C.;Sombra, A. S. B.
在Er3+和Yb3+掺杂的正铌酸镧(LNO)荧光粉的上转换(UC)中，正式比较了三种可能的热成像荧光粉的光学温度传感方法。研究中使用的三种方法分别是热耦合能级荧光强度比(FIR)、谷峰比(VPR)和非热耦合能级比(NTCL)。研究中的TCL是Er3+离子的H-2(11/2)->；I-4(15/2)和S-4(3/2)->；I-4(15/2)UC跃迁的强度之比。VPR方法在Er3+UC的H-2(9/2)->；I-4(15/2)转变中得到验证。通过NTCL技术研究了其他不符合TCL的跃迁比率。几组转变的比率，即S-4(3/2)->；i-4(15/2)/H-2(9/2)--gt；i-4(15/2)/S-4(3/2)->；i-4(15/2)/i-2(9/2)->；i-4(15/2)、S-4(3/2)->；i-4(15/2)/F-4(9/2)->；I-4(15/2)、F-4(7/2)->；I-4(15/2)/H-2(11/2)-->；I-4(15/2)、H-2(11/2)-->；I-4(15/2)/I-4(9/2)->；I-4(15/2)和H-2(11/2)-->；NTCL技术考虑为I-4(15/2)/(2)G(11/2)。此外，还分析了温度对发光颜色的影响，当温升从14K增加到300K时，发光颜色从黄色(0.3310；0.5990)变为绿色(0.2590；0.6740)。结果表明，LNO：Er3+/Yb3+荧光粉可以用于光学测温，该荧光粉有望成为一种高潜力的传感器，可用于TCL、VPR和/或NTCL方法从低温到室温工作。在LNO：Er/Yb材料的三种传感技术中，最突出的是NTCL，在300K时的相对灵敏度为1.19%K-1。
Three of the possible approaches to optical temperature sensing of a thermographic phosphor were formally compared in upconversion (UC) of Er3+ and Yb3+ doped lanthanum orthoniobate (LNO) phosphor. The three approaches used in the study were namely fluorescence intensity ratio (FIR) of thermally coupled levels (TCL), Valley to Peak ratio (VPR) and the ratio of non-thermally coupled levels (NTCL), respectively. The TCLs in the study were the ratio of intensities of H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) UC transitions of Er3+ ion. VPR method was verified within H-2(9/2) -> I-4(15/2) transition of Er3+ UC. The other ratios of transitions which are not fit in TCL were investigated through NTCL technique. Ratios of several sets of transitions namely S-4(3/2) -> I-4(15/2)/H-2(9/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2)/I-2(9/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2)/F-4(9/2) -> I-4(15/2), F-4(7/2) -> I-4(15/2)/H-2(11/2) -> I-4(15/2), H-2(11/2) -> I-4(15/2)/I-4(9/2) -> I-4(15/2) and H-2(11/2) -> I-4(15/2)/(2)G(11/2) were considered for NTCL technique. Moreover, the effect of temperature in the emission color was analyzed and a change from yellow (0.3310; 0.5990) to green (0.2590; 0.6740) was observed when the temperature rise has been increased from 14 to 300 K. Results obtained indicate that the LNO:Er3+/Yb3+ phosphor could be employed in optical thermometry and this phosphor would be a candidate with high potential as sensor operating from low to room temperature using TCL, VPR and/or NTCL methods. The most prominent sensing technique in the case of LNO:Er/Yb material among the three techniques is found to be NTCL with the high relative sensitivity of 1.19% K-1 at 300 K.