Photoluminescence profile mapping of Eu(iii) and Tb(III → IV)-embedded in quantum size SnO₂ nanoparticles

Abstract

Eu(iii) and Tb(iv) activators were embedded in quantum size SnO2 nanoparticles by a hydrothermal method and their morphologies, crystal structures and spectroscopic properties were examined by transmission electron microscopy, X-ray diffraction crystallography, UV-visible absorption, and 2D/3D-photoluminescence mapping.

Luminescent Eu(III) and Tb(III) activator ions in La(OH)3 and La2O3 nanowire matrices

“…In other words, Tb(III) was oxidized to Tb(IV) in the matrix upon thermal annealing. This is in good agreement with the literature [25][26][27][28][29][30][31].…”

“…The latter corresponds to the 5 L 6 ← 7 F 0 transition of Eu(III), which is most commonly used for the excitation of Eu(III). The emission spectrum of the 1 mol% Eu(III)-doped sample taken at ex = 300 nm revealed the 5 D 0 → 7 F J (J = 0-4) emission peaks, as expected: 5 D 0 → 7 F 1 (603 nm), 5 D 0 → 7 F 2 (618 nm), 5 D 0 → 7 F 3 (652 nm), and 5 D 0 → 7 F 4 (697 nm) [6,9,[25][26][27][28][29][30][31]. The peak at 603 nm ( 5 D 0 → 7 F 1 ) was significantly stronger than that ( 5 D 0 → 7 F 2 ) at 618 nm.…”

“…Upon 10 mol% doping, these two peaks were shifted to higher wavelength positions at 281 and 305 nm, and the peak intensity at 305 nm increased significantly. For the emission spectrum at an excitation wavelength of 240 nm, corresponding to the direct 5 L 10 ← 7 F 6 transitions of Tb(III), the emission peaks were observed at 491, 546, 586, and 621 nm, which were assigned to the 5 D 4 → 7 F J (J = 6, 5, 4, and 3) transitions, respectively [5,[25][26][27][28][29][30][31]. Upon annealing, the emission intensity increased dramatically due to the removal of quenching sites and an increase in crystallinity, as discussed above.…”

“…For the 10 mol% Tb(III)-doped sample, a new peak increased more drastically. This could be attributed to the charge transfer (O 2− → Tb 4+ ) absorption of Tb(IV) [25][26][27][28][29][30][31][32][33]. In other words, Tb(III) was oxidized to Tb(IV) in the matrix upon thermal annealing.…”

“…In this study, La(OH) 3 and La 2 O 3 was chosen as a host material and Eu(III) and Tb(III) activator ions were used as dopants to investigate the role of the host material and obtain the resulting photoluminescence profiles using a 2D and 3D-photoluminesce contour mapping technique [22][23][24][25][26][27][28][29][30][31]. This is the first detailed report of the luminescence properties of Eu(III) and Tb(III) ions doped in La(OH) 3 and La 2 O 3 matrices and the effects of a change in the crystal phase.…”