Thermal‐couple levels of ⁴S_3/2 and ²H_11/2 in Na(Ca, Sr)La(VO₄)₂:Er³⁺ phosphors for potential optical thermometers

Abstract

Novel green-emitting erbium(III) (Er 3+)-activated Na(Ca, Sr)La(VO 4) 2 phosphors with an interesting and stable trigonal structure were prepared. The crystal structure, elemental composition, morphology, photoluminescence, and sensing properties were investigated in detail. The color purity values of optimal NaSrLa(VO 4) 2 :0.05Er 3+ and NaCaLa(VO 4) 2 :0.05Er 3+ phosphors were calculated to be about 92.91% and 90.73% with the Commission Internationale de I'Eclairage color coordinates of (0.283, 0.684) and (0.295, 0.676), respectively. Meanwhile, the sensing property and cycling performance of those samples were also studied based on the thermalcouple levels of 4 S 3/2 and 2 H 11/2. The maximum absolute sensing sensitivity values of the NaCaLa(VO 4) 2 :Er 3+ and NaSrLa(VO 4) 2 :Er 3+ phosphors were found to be 9.23 × 10 −3 and 7.69 × 10 −3 K −1 while the relative sensing sensitivity values were found to be 1.15% and 1.20% K −1 , respectively. Furthermore, several repeated tests confirmed that the cycling performance was stable, demonstrating that the resultant samples with high and stable sensing sensitivity are great potential for optical thermometers.

Deep-red-emitting phosphors of Mn4+-activated tantalite for high-sensitivity lifetime thermometry and security films

“…The PL excitation (PLE) and PL emission spectra of samples were recorded with the aid of the same instruments as reported earlier. 41,42 The security films were fabricated by mixing the phosphors (0.5 g SITO:Mn 4+ and 0.05 g commercial YAG:Ce 3+ ) into a base resin (2.5 g) and curing agent (0.25 g), and then drying it in the air at 80 °C.…”

“…The PL excitation (PLE) and PL emission spectra of samples were recorded with the aid of the same instruments as reported earlier. 41,42…”

Visible and near-infrared luminescence properties of Nd3+/Yb3+ co-doped Gd2O3 phosphors for highly sensitive optical thermometry

“…6,7 In particular, optical thermometers are gaining increasing research interest in the biomedical field. 8,9 They are appropriate to probe temperature in live biological systems as a noninvasive spectroscopic method. To date, many extract temperature sensitive spectral features, such as the fluorescence intensity ratio (FIR), emission intensity, emission bandwidth, emission peak position, and so-called temperature readouts, have been demonstrated.…”