Excitation and luminescence of rare earth-doped lead phosphate glasses

Chemical tunability of europium emission in phosphate glasses

“…Indeed, most of these studies were focused on the understanding of the structural environment of Eu 3+ ions, due to the narrow and almost monochromatic 5 D 0 -> 7 F 2 transition at ~ 613 nm and to its long lifetimes [e.g. 2,15,16]. Nevertheless, in the past decades many studies tried to influence the valence states of europium ion in solid-state materials, mainly in borate, boro-silicate and boro-phosphate glasses, or silicate and aluminosilicate glasses [3-5 and references therein].…”

New apatite‐type phosphor Ca9La(PO4)5(SiO4)F2:Tb3+,Dy3+ with improved color rendering index

“…The ratio of integrated emission intensity of the 5 D 3 → 7 F J ( J = 3–6) to the 5 D 3 → 7 F J transitions is referred as the green‐to‐blue luminescence intensity ratio (G/B factor) . The G/B (Tb 3+ ) factor could describe the asymmetry of the local environment around the optically active dopant and covalent/ionic bonding between Tb 3+ and O 2− . Calculated G/B factor for Tb 3+ ions is helpful to understand the crystal environment of dopant, and could provide some identifications for the energy transfer between the Tb 3+ and Dy 3+ ions.…”

“…30 The G/B (Tb 3+ ) factor could describe the asymmetry of the local environment around the optically active dopant and covalent/ionic bonding between Tb 3+ and O 2− . 31 Calculated G/B factor for Tb 3+ ions is helpful to understand the crystal environment of dopant, and could provide some identifications for the energy transfer between the Tb 3+ and Dy 3+ ions. From x = 0.01 to x = 0.05 the transitions from 5 D 3 state are comparable in intensity with transitions from 5 D 4 state ( Figure 4A).…”

Luminescence investigations of rare earth doped lead-free borate glasses modified by MO (M = Ca, Sr, Ba)

“…Moreover, the energy gap (6950 cm À1 ) between the 1 D 2 excited state and the next 1 G 4 lower-lying state of Pr 3þ [58] is significantly lower than the energy gap (12500 cm À1 ) between the 5 D 0 excited state and the next 7 F 6 lower-lying state of Eu 3þ , respectively. Our previous investigations obtained for lead phosphate glasses indicate that luminescence lifetime of the excited state of Ln 3þ increases with increasing energy gaps between excited state and lower-lying state of Ln 3þ [59]. In this case, it was suggested that separation energies between excited state and lower-lying state of trivalent Ln 3þ (Ln ¼ Pr, Eu) give also important contribution to the luminescence decay kinetics and their direction of changes with increasing/decreasing ionic radius of glass modifiers MO (M ¼ Ca, Sr, Ba) in lead-free borate glass host.…”