Thermosensitive Tm3+/Yb3+ co-doped oxyfluorotellurite glasses – spectroscopic and temperature sensor properties

• Published in: Journal of alloys and compounds 2020-05, Vol.823, p.153753, Article 153753
• Main Authors: Klimesz, Barbara, Lisiecki, Radosław, Ryba-Romanowski, Witold
• Format: Article
• Language: English
• Subjects: Absorption spectra; Differential thermal analysis; Emission analysis; Emission spectra; Excitation; Fluorescence; Glass; Luminescence; Luminescent temperature sensors; Mathematical analysis; Oscillator strengths; Rare earth-doped oxyfluorotellurite glasses; Sensitivity; Spectroscopy properties; Stability analysis; Stability criteria; Tellurium dioxide; Temperature; Temperature effects; Temperature sensors; Thermal properties; Thermal stability; Thulium; Transition probabilities; Upconversion; Ytterbium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.153753

Oxyfluorotellurite (65-x)TeO2–20ZnF2–12PbO–3Nb2O5–xTm2O3 (x = 0.5, 2 and 5) and (65-x-y)TeO2–20ZnF2–12PbO–3Nb2O5–xTm2O3–yYb2O3 (x = 0.5, y = 2 and x = 0.5, y = 5) glass systems were manufactured. Glass thermal stability was examined by means of differential thermal analysis (DTA) and some thermal stability criteria ΔT, H’ and S were determined. Absorption spectrum was utilized to prepare Judd-Ofelt (J-O) calculations and consequently oscillator strengths, intensity parameters Ω2,4,6, radiative transition probabilities, branching ratios and radiative lifetimes of luminescent levels were estimated. Emission spectra and luminescence decay curves were measured as a function of temperature in the 300–625 K range. Based on the upconversion luminescence of Tm3+ the optical temperature sensor qualities have been evaluated for Tm3+/Yb3+ co-doped sample. The fluorescence intensity ratio (FIR) between transitions 700 nm (Tm3+:3F2,3 → 3H6)/800 nm (Tm3+:3H4 → 3H6) for 975 nm excitation and 700 nm (Tm3+:3F2,3 → 3H6)/470 nm (Tm3+:1G4 → 3H6) for 803 nm excitation were determined and an adequate relative thermal sensitivity S was estimated. The significant value of relative thermal sensitivity 1.12 %K−1 was determined when NIR Yb3+ and Tm3+ emission bands were analyzed, however. Effective emission cross section was calculated for 3F4 → 3H6 potential laser transition of thulium around 1.9 μm in single-doped Tm3+ glass. Furthermore, effect of temperature on down-converted and up-converted thulium and ytterbium emission and on relaxation dynamic of involved excited states was studied in details. •Oyfluorotellurite glasses singly-doped and co-doped Tm3+ and Yb3+ were prepared.•Thermal and optical properties of tested materials were determined.•Thermal properties of glasses depend on the Tm3+/Yb3+ ions concentrations.•Investigated materials have advantageous properties for NIR optical gain.•TZPN glasses activated with RE3+ ions can be used in luminescence thermometry.