Preparation of cereal-like Y V O₄:Ln^{3 +}(Ln = Sm, Eu, Tb, Dy) for high quantum efficiency photoluminescence

Abstract

In this work, preparation of cereal-like architectures Y V O(4) and Y V O(4):Ln(3 + ) (Ln = Eu, Sm, Dy, Tb) was initiated using a hydrothermal method. During the formation reaction, Na(3)C(6)H(5)O(7).2H(2)O was used to effectively adjust the concentration of Y(3 + ) species necessary for cereal-like architectures. Phase structure, surface chemistry, morphology, and photoluminescence were characterized by x-ray powder diffraction, Fourier transformed infrared spectra, scanning electron microscopy, transmission electron microscopy, and photoluminescence spectra. All samples crystallize in a tetragonal zircon structure, stably showing a homogeneous cereal-like morphology. This special morphology was constructed by self-assembly of tiny primary particles with a dimension of 31-32 nm. With increasing atomic number of Ln(3 + ), the lattice dimension of the cereal architectures became monotonously enlarged. This cereal-like architecture is proved unique in significantly improving the quantum efficiencies: the internal quantum efficiencies of (5)D(0) for Ln = Eu and (4)F(9/2) for Ln = Dy were 14.6% and 11.4%, respectively, which are all superior over those of the counterparts of nanoparticles reported in the literature. The average lifetime of the (5)D(0) level for Ln = Eu was calculated to be 98 micros, which is longer than that of 50 micros of the (4)F(9/2) level for Ln = Dy. The strong photoluminescence might be the consequence of the effective energy transfer due to the greatly reduced defect centers from this special self-assembly structure.

Synthesis characterization and luminescence studies of gamma irradiated nanocrystalline yttrium oxide

“…Numerous techniques such as sol gel [5], co-precipitation [6], solid state reaction [7], hydrothermal [8] and solution combustion [9][10][11] have been reported for synthesis of nanomaterials. Among these, solution combustion method has greater advantages since it produces crystalline materials at low temperature with high surface to volume ratio.…”

Optical and structural properties of nanostructured CeO2:Tb3+ film

“…Furthermore, the excitation at near-ultraviolet wavelength is preferable to the use of LEDs as light sources. In contrast to rare earth doped nanophosphors such as CePO 4 :RE, Y 2 O 3 :RE, CeF 3 :RE or NaYF 4 :RE, RE doped cerium oxide films in view of luminescence has been relatively less studied [9][10][11][12][13]. Tetravalent cerium ions (Ce 4+ ) have no 4f electron.…”

Luminescent and magnetic properties of YVO4:Ln3+@Fe3O4 (Ln3+=Eu3+ or Dy3+) nanocomposites

“…Three main bands at 397 nm, 467 nm and 538 nm are corresponding to the electron transitions from the 7 F 0 -5 L 6 , 7 F 0 -5 L 2 and 7 F 0 -5 L 1 , respectively. This phenomenon demonstrates the presence of an energy transfer from VO 4 3− groups to Eu 3+ [20,21] when the YVO 4 :Eu 3+ phosphors were coated with Fe 3 O 4 nanoparticles in Fig. 2(c), there are not the three peaks.…”

“…The other part is luminescent materials. Due to their good optical properties, rare-earth (RE) doped yttrium vanadate (YVO 4 ) as luminescent materials has been widely studied [7][8][9][10]. Investigations show that nanosized YVO 4 :Ln 3+ phosphors have a significant application in a high definition flat display panel and potential applications in biology [11][12][13].…”