Rugby-ball-shaped Na0.5La0.5MoO4:Eu3+ 3D architectures: synthesis, characterization, and their luminescence behavior

Abstract

A series of first-, second-, and third-generation dendronic triazolo-pyridazinones were synthesized in good yields via the Cu I -catalyzed azide-alkyne cycloaddition reactions of 4,6-diphenyl-2-(prop-2-yn-1-yl)pyridazin-3(2H)-one, possessing a terminal alkyne functional group with aromatic mono-and diazides with long alkyl and chiral glycol side-chain substituents. The chemical structures of the new compounds were characterized using different spectroscopic methods. The morphology of the dendrons was examined using the scanning electron microscope (SEM) analysis, which revealed the formation of highly ordered nanofiber and nanorod aggregations, directed by π-stacking interactions and van der Waals forces. Graphical abstractKeywords Dendron · Azide-alkyne cycloaddition · Self-assembly · Pyridazin-3(2H)-one · Nanofiber · Nanorod

Synthesis, luminescence and photometric characteristics of Ca0.5La(MoO4)2:Ln3+ (Ln=Eu, Tb, Dy) phosphors

“…Fig. 7b shows the concentration-dependent PL emission spectra of the Ca 0.5 La 1 (MoO 4 ) 2 :Dy 3þ samples with Dy 3þ concentrations (4,8,12,16, and 20 mol%) excited at 388 nm. The PL emission intensity is significantly affected by increasing the doping concentration of Dy 3þ ions and reaches the highest intensity at the concentration of 12 mol% Dy 3þ .…”

“…The molybdate compounds with scheelite-type structures, where molybdenum atoms are coordinated tetrahedrally, show promising applications in optoelectronics [16,17]. However, the phosphor color rendering index (CRI) and luminous efficacy require improvement before they can be used for WLEDs applications if their excitation wavelengths are not coupled with the emission of blue LEDs.…”

“…In this study, we report on the synthesis of Ca 0.5 La(MoO 4 ) 2 :Ln 3þ (where Ln ¼ Eu, Tb, Dy) phosphors (where Ln ¼ Eu, Tb, or Dy in different concentrations such as 4,8,12,16, and 20 mol%) by a conventional solid-state reaction method. The crystalline structure and phase purity of the samples were analyzed by XRD.…”

“…The XRD patterns show that these samples belong to the single-phase scheelite-type tetragonal structure in the space group I41/a. The ionic radii of La 3þ (R La ¼ 1 16. Å), Eu 3þ (R Eu ¼ 0.947 Å), Tb 3þ (R Tb ¼ 0.923 Å) and Dy 3þ (R Dy ¼ 0.912 Å) [28e30] are different.…”

Up/down conversion luminescence and charge compensation investigation of Ca0.5Y1−x(WO4)2:xLn3+ (Ln=Pr, Sm, Eu, Tb, Dy, Yb/Er) phosphors

“…The intense emission peak found at 617 nm under 395 nm UV excitation is due to the 5 D 0 → 7 F 2 electric-dipole transition with hypersensitive red emission that is parity forbidden (∆J = 2). Two sub-peaks arise due to Stark energy splitting, that is, (2J + 1) Stark components of J-10 degeneracy splitting [24][25][26][27][28]. The dominance of the electric-dipole transition confirms that Eu 3+ ions are located at sites without inversion symmetry [23,29].…”