Spectroscopic investigation of Er3+ doped BaF2 single crystal

Luminescence Properties and Judd–Ofelt Analysis of Various ErF3 Concentration-Doped BaF2 Crystals

“…Figure 2 shows the XRD pattern for the BaF 2 : 0.08 mol% ErF 3 -grinded crystal sample. The diffraction peaks correspond to the cubic phase according to ICDD Cards No 00-004-0452, No 01-085-1341 and No 00-002-1157, and in good agreement with the published data of Bitam et al [16]. No additional peaks that can be associated with undesired impurities were observed.…”

“…Other authors [3,4,6,29] also reported this behavior. The majority of studies regarding luminescence RE ion-doped BaF2 v refer to emissions obtained mainly by pumping in the IR domain [14][15][16]. Comparing the emission spectra of our samples by excitation at λex = 290 nm and λex = 380 nm, it was concluded that the emission at 321 nm is the most intense (see Figures 5a and 6a).…”

Spectroscopic Properties of Erbium-Doped Oxyfluoride Phospho-Tellurite Glass and Transparent Glass-Ceramic Containing BaF2 Nanocrystals

“…The optical properties of BaF 2 make it a universal optical material. Optical properties of BaF 2 are related to the structural and electronic properties of barium difluoride such as very large bandgap (11 eV), the low phonon energy (319 cm −1 ) and the large optical transparency from ultraviolet (UV) to far-infrared (FIR) from 0.2 to 14.0 μm [132,133].…”

An up-conversion luminophore with high quantum yield and brightness based on BaF2:Yb3+,Er3+ single crystals

“…Figure S3 demonstrates a number of possible ways ( and ) how the Er 3+ : 4 I 9/2 level can be populated with a further transition to {Er 3+ : 4 I 11/2 & Yb 3+ : 2 F 5/2 }) manifold. In the crystals with low maximum phonon energy (240 cm -1 for BaF 2 ), the rate of multiphonon relaxation for the 4 I 9/2 ⟶ 4 I 11/2 transition (with the energy gap of ΔE=2000 cm -1 ) is very slow and, thus, decay time is approaching the radiative lifetime of the 4 I 9/2 state exceeding 10 ms. 76 Thus, this weakly emissive, but long-lived state can be considered as an additional reservoir (in parallel with the {Er 3+ : 4 I 11/2 & Yb 3+ : 2 F 5/2 } manifold and the Er 3+ : 4 I 13/2 state) of metastable excited states influencing on DS and UC processes. Under this circumstance, the moderate and high concentrations of Er 3+ assist the population of the 4 I 9/2 state increasing the lifetime of 4 S 3/2 , 4 F 9/2 , and {Er 3+ : 4 I 11/2 & Yb 3+ : 2 F 5/2 } states.…”

“…Altogether, the obtained values of the radiative decay times are close to the results of other studies devoted to optical properties of Er 3+ ions in fluoride single crystals and micropowders. 76,[82][83][84] Whereas an acceptable level of conformity between theoretical prediction ( in Table S9) and experimental results ( in Table S6) for the 4 F 9/2 ⟶ 4 I 15/2 transition exists (the relative difference doesn´t exceed 20 % in most ( -)/ cases), for the case of 4 S 3/2 ⟶ 4 I 15/2 and 4 I 13/2 ⟶ 4 I 15/2 transitions a discrepancy between quantum yields extracted from the Judd-Ofelt calculation and the experimental one is significant. The values of estimated via Judd-Ofelt analysis always exceed unity for the 4 I 13/2 ⟶ 4 I 15/2 transition, because measured decay times () are longer than predicted radiative lifetimes ( r ).…”