High sensitive Ln3+/Tm3+/Yb3+ (Ln3+ = Ho3+, Er3+) tri-doped Ba3Y4O9 upconverting optical thermometric materials based on diverse thermal response from non-thermally coupled energy levels

Optical temperature sensing and luminescent switching properties in Pr/Er‐doped (K0.5Na0.5)NbO3 materials

“…Compared with thermally coupled energy levels (TCLs), the NTCLs are no longer limited by the energy separation, so it is possible to produce higher temperature sensitivity. 28 In this work, two emitting energy levels are coming from two luminescent centers ( Figure 7A,B), then the difference of temperature response ability to temperature between NTCLs and TCLs is large. 29 Compared with the materials doped with single rare-earth ions or sensitized with Yb ions, the KNN: Pr/ xEr materials exhibit the tuned temperature sensitivity by controlling emission or excitation bands, as shown in Table 2.…”

“…Generally, the emission peaks at 606 nm and 550 nm are nonthermally coupled energy levels (NTCLs). Compared with thermally coupled energy levels (TCLs), the NTCLs are no longer limited by the energy separation, so it is possible to produce higher temperature sensitivity . In this work, two emitting energy levels are coming from two luminescent centers (Figure A,B), then the difference of temperature response ability to temperature between NTCLs and TCLs is large …”

Preparation, luminescence properties, and application of temperature sensing and anti‐counterfeiting of La2MgTiO6:Yb3+/Ln3+/Mn4+

“…What's more, increasing the values of the FIRs is an effective way to increase S A values 40–41 . In particular, the LMT:Yb 3+ /Ln 3+ and LMT:Yb 3+ /Ln 3+ /Mn 4+ phosphors have large absolute S A values compared to literature‐reported Yb 3+ /Ln 3+ doped oxides and fluorides (Table 2), 42–46 indicating their potential applications in temperature sensing. $$\begin{equation}{\rm{FIR}} = {I_1}{\rm{/}}{I_2} = A\,{\rm{exp}}\left( { - \Delta E/kT} \right),\end{equation}$$ $$\begin{equation}{S_A} = A\left( {\Delta E{\rm{/}}k{T^2}} \right){\rm{exp}}\left( { - \Delta E{\rm{/}}kT} \right).\end{equation}$$ Here, I 1 and I 2 are the integrated intensity corresponding to the emissions, A is the fitting constant, Δ E is the energy difference between energy levels, k is Boltzmann's constant, and T is the absolute temperature.…”

“…The absolute sensitivities of all samples increase or decrease monotonically with increase in temperature, reaching the maximum at 340 or 480 K. Table 1 S A values. [40][41] In particular, the LMT:Yb 3+ /Ln 3+ and LMT:Yb 3+ /Ln 3+ /Mn 4+ phosphors have large absolute S A values compared to literature-reported Yb 3+ /Ln 3+ doped oxides and fluorides (Table 2), [42][43][44][45][46] indicating their potential applications in temperature sensing.…”

Investigation on the Fluorescence Intensity Ratio Sensing Thermometry Based on Nonthermally Coupled Levels

“…So searching for a new temperature measurement method that is more suitable for the needs of the times has become a challenging frontier. Some previous works have referred to the temperature measurement by utilizing nonthermal coupling levels. − However, most of them were based on the experimental data fitting of one or two kinds of materials, and their universality was a bit low. Also, a few of them systematically compared it with the thermal coupling level temperature measurement method to explore the advantages of the nonthermal coupling level temperature sensing method, nor did they apply the nonthermal coupling level thermometry to biological applications.…”