New melilite (Ca,Sr,Ba)₄MgAl₂Si₃O₁₄:Eu²⁺ phosphor: structural and spectroscopic analysis for application in white LEDs

Abstract

Tunable asymmetric broad-band emission ranging from blue to green region of the spectra was obtained.

A Phosphosilicate Compound, NaCa3PSiO8: Structure Solution and Luminescence Properties

“…The decay profile monitored at 505 nm was found to have a multicomponent decay mechanism. The decay profile shown in Figure c is fitted with a three-component exponential decay model of the form, where I 1 , I 2 , and I 3 are constants and τ 1 , τ 2 , and τ 3 are the decay times of the constituent components. The effective lifetimes of the Eu 2+ ions in the excited states of the host structure can be calculated using the equation and were found to be 0.40 and 0.26 μs for activator concentrations of 0.0125 and 0.025 mol, respectively.…”

Synthesis of Novel Melilite-Type Iron/Cobalt Oxides and Their Oxygen Evolution Reaction Electrocatalytic Activity

“…Melilite-type compounds are described with a general formula of A 2 BC 2 X 7 and crystallize in the tetragonal system, schematically illustrated in Figure . Larger cations of alkali metals, alkaline-earth metals, and rare-earth metals are located at the A sites, − and smaller cations such as Zn, Al, Si, Ge, and TMs occupy the B and C sites. ,− The X sites contain O 2– , N 3– , and S 2– anions. − Importantly, both of the B and C sites are tetrahedrally coordinated (CN = 4), forming a two-dimensional network in the crystallographic ab -plane. The A sites are located between two blocks of the tetrahedral networks to form a layered structure.…”

An efficient green-emitting Ba5Si2O6Cl6:Eu2+ phosphor for white-light LED application

“…The electronic transition 4f 6 5d 1 / 4f 7 of Eu 2+ is strongly sensitive to its surrounding environment, i.e., symmetry, covalence, bond length, crystal-eld strength. 21,22 Hence Eu 2+ -doped suitable hosts are extensively studied because of their potential applications as phosphor materials. Silicate-based materials have been a favourable host for Eu 2+ because of their strong absorption in the UV-to-visible spectral region, thus providing strong luminescence.…”