Influence of La substitution on local structural and photoluminescence properties of SrTiO3:Pr phosphor

Abstract

Pr 3+-doped perovskite-based SrTiO 3 phosphors have been developed as a potential red phosphor. In this paper, we report the substitution of La 3+ ions for Sr 2+ ions in order to promote Sr vacancies to further enhance photoluminescence. Given that the La content increases, an enhancement in the intensity of all emissions is observed, mainly for 1 D 2-3 H 4 and 3 P 0-3 H 6 transitions. This enhancement of photoluminescence emissions is associated with disorder in the lattice caused by La incorporation. Raman measurements and X-ray absorption near edge structure (XANES) spectra at the Ti K-edge identify this disorder as a function of the La content.

Local and electronic structure of Sr1-Gd TiO3 probed by X-ray absorption spectroscopy

“…In order to comprehend the origin of the oscillations observed in the post-edge region of these spectra, we performed successfully ab initio calculations of theoretical XANES spectra at Sr K-edge as a function of the cluster radius. The calculation was performed through ab initio FEFF code [30] with cluster radius of 6.0, 4.77 , 3.91 and 3.38 Å and crystallographic model according to cubic SrTiO3 structure with Pm-3m space group [35]. atom, whereas the third shell with 6 Sr atoms is added in the cluster with radius equal to 3.91 Å.…”

“…The experimental EXAFS spectra for our set of samples were obtained with the back Fourier transform (FT) between 1.0 and 5.5 Å. The theoretical model used in the fits were generated from FEFF9 code and structural data considering SrTiO3 structure [35]. Fig.…”

Radiation Response Characteristics of Pr3+-activated SrO–Al2O3–TeO2 Glasses

“…All the PSAT glasses showed excitation peaks at 445, 473, and 484 nm due to the 4f-4f transitions ( 3 H 4 → 3 P 2 , 3 H 4 → 3 P 1 , and 3 H 4 → 3 P 0 , respectively) of Pr 3+ . (26)(27)(28)(29)(30) Moreover, the QY values of the PSAT glasses were 26% (0.1PSAT), 17% (0.5PSAT), and 8% (1.0PSAT), as listed in Table 3, and the QY values decreased with increasing Pr 2 O 3 concentration, probably because of concentration quenching.…”

Development of deep red–emitting CaBiVO5:Pr3+ phosphor for multifunctional optoelectronic applications

“…44 The low symmetry sites around Pr 3+ ion can mix the opposite parity into 4f configurational levels, consequently increasing the probability of 1 D 2 → 3 H 4 transition of Pr 3+ ions. 42,45 Moreover, the emission at 656 nm is attributed to the hypersensitive 3 P 0 → 3 F 2 transition of Pr 3+ (ΔS = 0, ΔJ = 2; S = spin angular momentum, J = total angular momentum), which is a forced electric dipole transition, and strongly dependent on the field environment around Pr 3+ ions. 40 Furthermore, Figure 6A epitomizes the improvement in red emission intensity of CBV: Pr 3+ phosphor with increasing concentration of Pr 3+ ions up to 1.25 mol%.…”

“…The emission spectra reveals various sharp bands located at 533, 547, 583, 608, 620, 656, 680, and 693 nm attributed to 3 P 1 → 3 H 5 , 3 P 0 → 3 H 5 , 3 P 1 → 3 H 6 , 1 D 2 → 3 H 4 , 3 P 0 → 3 H 6 , 3 P 0 → 3 F 2 , 3 P 0 → 3 F 3 , and 1 D 2 → 3 H 5 transitions of Pr 3+ ions, respectively. [37][38][39][40][41][42][43] The emission peak located at 608 nm ( 1 D 2 → 3 H 4 ) dominates among all the peaks present in the emission spectra. In the present case, there is a possibility of inhomogeneous crystal field and low symmetry around Pr 3+ ions, which may be ascribed to minute Ca/Bi disordered ratio in the CBV lattice structure.…”