Highly sensitive optical thermometry based on Tm3+/Yb3+ doped NaGd2F7 glass ceramics

Er3+/Yb3+ ions doped chiral inorganic nanostructured BiOCl phosphor as a novel temperature sensing material

“…Based on the above observation, two kinds of FIR technique, using TCLs and NTCLs, can be employed for temperature sensing. First, it is well known that the FIR of the emissions from the thermally coupled 2 H 11/2 and 4 S 3/2 levels follows the Boltzmann distribution 23,24 : $$$$\begin{equation}{\mathrm{FIR}} = \ \frac{{{I}_{525}}}{{{I}_{543}}} = A{\mathrm{ exp }}(\frac{{ - \Delta E}}{{kT}})\end{equation}$$$$where I 525 and I 543 are the integrated intensities corresponding to the 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions, respectively, A is the pre‐exponential constant, $${{\Delta}}$$ E is the energy difference between the 2 H 11/2 and 4 S 3/2 levels, k is Boltzmann's constant, and T is absolute temperature. The curves of FIR versus T measured for the D‐BYEP are presented in Figure 5C.…”

“…Based on the above observation, two kinds of FIR technique, using TCLs and NTCLs, can be employed for temperature sensing. First, it is well known that the FIR of the emissions from the thermally coupled 2 H 11/2 and 4 S 3/2 levels follows the Boltzmann distribution 23,24 : 25,26 According to Refs. 9 and 27, the S A and S R can be calculated by the following equations:…”

Regulating the upconversion luminescence properties of Tm3+/Yb3+-codoped ZrScW2PO12 microparticles with a negative thermal expansion effect through thermal stimulation for optical thermometry

“…Furthermore, it was reported that the 3 F 2,3 and 3 H 4 levels are related to the TCLs of Tm 3+ , which means that the 3 F 2,3 level can be populated from the 3 H 4 level via thermal excitation, resulting in the enhanced population of the 3 F 2,3 level. 40 Obviously, the depopulation of the 3 H 4 level will also reduce the number of electrons at the 1 G 4 level (see Fig. 4(c)).…”

Comparative studies of upconversion luminescence and optical temperature sensing in Tm3+/Yb3+ codoped LaVO4 and GdVO4 phosphors

“…14 Lanthanide ions with a larger ionic radius prefer to choose monazite structure because of its higher oxygen coordination number (9). 15 On the line of YVO 4 and GdVO 4 hosts it is expected that LaVO 4 can be a good candidate for strong upconversion emission which is also revealed by Shao et al 17 It is feasible to create multi-colored emission by doping with various rare earth (Ln 3+ ) ions, such as red from Eu 3+ , green from Er 3+ , and blue from Tm 3+ ions. The LaVO 4 is substantially less expensive and is based on a resource that is far more abundant than Y.…”

“…Rare earth doped upconverting phosphors, which convert lower-energy photons to higher-energy photons, have triggered widespread interest in recent decades because of their excellent properties and vast potential applications in solar cells, display devices, light emitting diodes, bio-imaging, optical thermometry etc. [1][2][3][4][5][6][7][8] Nevertheless, upconversion (UC) luminescent materials are currently hampered by low emission efficiency which restricts their eld applications in several cases. Therefore, it is crucial to nd ways to improve their UC efficiency.…”