Thermally stable orange-red emitting Ba2SiO4:Sm3+ phosphor: Synthesis and luminescence properties

Advantageous Occupation of Europium(III) in the B Site of Double-Perovskite Ca2BB′O6 (B = Y, Gd, La; B′ = Sb, Nb) Frameworks for White-Light-Emitting Diodes

“…Recently, the activation energy (ΔE) was used to estimate the strength of the thermal quenching, though its value could be affected by various factors, such as host material, R 2 value of the fitting line (fitting degree), emission intensity, and excitation wavelength. However, to study the thermal quenching in more depth, the ΔE value could be defined as 51,52…”

“…Recently, the activation energy ( ΔE ) was used to estimate the strength of the thermal quenching, though its value could be affected by various factors, such as host material, R 2 value of the fitting line (fitting degree), emission intensity, and excitation wavelength. However, to study the thermal quenching in more depth, the ΔE value could be defined as , where I 0 and I represent the emission intensities at temperature T = 0 and T , respectively and A is a constant, while the k is the Boltzmann coefficient. Subsequently, the plot of 1/ kT versus ln­( I 0 / I – 1) of the resultant samples are shown in Figure S5a–f (SI).…”

Valence state switching and reversible emission tunability of A2SiO4 (A = Ba, Sr, and Ca) with two-site substitution of Eu ions through simple thermal treatment

“…These values indicate that the Rietveld refinement results were appropriate. Through Rietveld refinement analysis, we confirmed that the structure of Ba 2 SiO 4 :Eu was orthorhombic ( Pnma ), the structure of Sr 2 SiO 4 :Eu was a mixture of orthorhombic (α′, Pnma ) and monoclinic (β, P 2 1 / c ), and the structure of Ca 2 SiO 4 :Eu was monoclinic (β, P 2 1 / c ) [ 6 , 18 , 30 ]. Interestingly, the weight ratios of the α′- and β-phases of Sr 2 SiO 4 :Eu were approximately 1:1 in the H 2 annealed sample, but the ratio changed to 1:2 in the O 2 annealed sample.…”

Superlattice-stabilized structure and charge transfer assisted photoluminescence enhancement in a samarium-doped high entropy perovskite oxide

“…The other narrow peaks with lower intensity centered at 363 nm, 379 nm, 420 nm, 438 nm, 467 nm and 482 nm are associated with transitions from the ground 6 H 5/2 state to the 4 D 3/2 , 4 D 1/2 , 6 P 5/2 , 4 G 9/2 , 4 I 13/2 and 4 I 11/2 levels. 34 Below 350 nm, a broad band with a maximum at 290 nm is observed, which is associated with the charge transfer state (CTS) between rare earth ions and oxygen anions. This can be inferred from a great number of studies where the spectral range of 200–350 nm is attributed either to charge transfer processes from oxygen to Sm 3+ or to overlapping lines from host absorption and O 2− → Sm 3+ CTSs.…”