Polyethylene glycol assisted facile sol-gel synthesis of lanthanum oxide nanoparticles: Structural characterizations and photoluminescence studies

Abstract

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Up‐Conversion Luminescence Enhancement and Temperature Sensitivity Properties of La2O3: Yb3+/Er3+ Nanoparticles Induced via Tri‐Doping Li+ Ions

“…FT‐IR spectra of La 2 O 3 : Yb 3+ /Er 3+ /Li + nanoparticles were exhibited in Figure 6. The absorption peaks at 450 and 650 cm −1 were attributed to the vibration mode of La−O, which were in line with the reported cutoff phonon energy and almost identical for all samples [15] . Therefore, introducing Li + ions can't change the lattice vibration of La 2 O 3 host.…”

“…Therefore, when the Li + concentration was below 10 mol%, the influence of Li + ion lattice substitution on La 2 O 3 lattice exceeded the influence of Li + substitution, while when it was above 10 mol% and below 15 mol%, the Li + ion substitution was dominant. Table 1 gave the lattice constant of all samples, the values of a, b, c can be obtained by XRD spectra, and the unit cell volume V can be obtained by the following equation: [15] (1)…”

“…Materials, synthesis, and characterization methods of La 2 O 3 : Yb 3 + /Er 3 + /Li + nanoparticles (7/1/x mol%, x = 0, 3,5,7,10,13,15) are listed in the supporting information.…”

“…The absorption peaks at 450 and 650 cm À 1 were attributed to the vibration mode of LaÀ O, which were in line with the reported cutoff phonon energy and almost identical for all samples. [15] Therefore, introducing Li + ions can't change the lattice vibration of La 2 O 3 host. The absorption bands at 830 cm À 1 and 1430 cm À 1 were attributed to CO 3 2À groups, and the absorption band at 3400 cm À 1 originated from OH À groups.…”

“…[13] La 2 O 3 has excellent thermal stability, lower photon energy and lower toxicity, which are favorable for efficient UC emission. [14,15] Compared to other oxides, such as, Y 2 O 3 , [16] Gd 2 O 3 , [17] and ZnO, [18] La 2 O 3 is cheaper and more abundant. Er 3 + ion is recognized as a good source of green light, which can emit green emission through 2 H 11/2 !…”