Enhancement of Vibrant Up-Conversion in (Ca,Sr)F:Er,Yb,Al Phosphors via Energy Transfer, Localized Interstitial Distortion, and Au Nanostructures.

A remarkable increase in the luminescent intensity of Er-doped CaF up-conversion phosphors was achieved, showing an approximate enhancement of over 1100-fold. This enhancement was realized by incorporating Yb, Al, Sr, and gold nanospheres and nanorods. The substantial improvement in up-converting luminescence effectively enhances sensitivity and efficiency at low excitation power densities.

Photoluminescence Spectra Correlations with Structural Distortion in Eu- and Ce-Doped YAl(Mg,Ge)O ( = 0, 1, 2) Garnet Phosphors.

Garnet-type materials consisting of YAl(Mg,Ge)O ( = 0, 1, 2), combined with Eu or Ce activator ions, were prepared by a solid-state method to determine the structural and optical correlations. The structure of YAl(Mg,Ge)O ( = 1, 2) was determined to be a cubic unit cell (Ia-3d), which contains an 8-coordinated Y site with octahedral (Mg,Al)O and tetrahedral (Al,Ge)O polyhedra, using synchrotron powder X-ray diffraction. When Eu or Ce ions were substituted for the Y site in the YAl(Mg,Ge)O host lattices, the emission spectra showed a decrease in the magnetic dipole - Eu transition and a redshift of the - Ce transition, related to centrosymmetry and crystal field splitting, respectively.

Insights of Peculiar Green-Yellow Emission Occurrence in Ce-Doped Barium Yttrium Orthogermanate Phosphors.

The BaCeNaYGeO orthogermanate phosphor, prepared by LiCl flux assistance under a reducing atmosphere, exhibited a mysterious green-yellow emission at 298 K. A blue-emitting orthogermanate phosphor was expected to be achieved through the lower d-band of Ce ions in the host structure owing to their optical structure geometry. Oxygen vacancies were observed in the phosphors through investigating bond-length fluxations, the oxygen 1s profile, and the Ge/Ge oxidation state, using synchrotron X-ray diffraction refinement, X-ray photoelectron spectroscopy, and Ge K-edge X-ray absorption near-edge structure spectra, respectively.

Self-Activating Strontium Orthoborate Blue Phosphors Induced by Cation and Anion Deficiencies and Their Rare-Earth-Free White Ultraviolet Light-Emitting Diodes.

Self-activating blue-light-emitting strontium orthoborate phosphors, viz., SrBO and SrBO ( ranges from -0.3 to 0.

Nonstoichiometric LaOF Structure and Its Green Luminescence Property Doped with Bi and Tb Ions for Applying White UV LEDs.

Red-green-blue phosphors excited by ultraviolet (UV) radiation for white light LEDs have received much attention to improve the efficiency, color rendering index (CRI), and chromatic stability. The spectral conversion of a rare-earth ion-doped nonstoichiometric LaOF host was explored with structural analysis in this report. The nonstoichiometric structure of a LaOF compound, synthesized by a solid-state reaction using LaO and excess NHF precursors, was analyzed by synchrotron X-ray powder diffraction.

Enhancement in Electromagnetic Wave Shielding Effectiveness through the Formation of Carbon Nanofiber Hybrids on Carbon-Based Nonwoven Fabrics.

The selective hybrid formation of numerous tiny carbon nanofibers (CNFs) in carbon-based nonwoven fabrics (c-NFs), namely CNFs formed only on the surfaces of individual carbon fibers (i-CFs) constituting c-NFs and not on the surfaces of carbon microcoils (CMCs), could be formed by the incorporation of H gas flow into the CH + SF gas flow in a thermal chemical vapor deposition system. On the other hand, the nonselective hybrid formation of numerous tiny CNFs in c-NFs, that is, tiny CNFs formed on the surfaces of both i-CFs and CMCs, could be achieved by simply modulating the SF gas flow on and off in continuous cycles during the reaction. Detailed mechanisms are suggested for the selective or nonselective formation of tiny CNFs in c-NFs.

Enhancement of Electromagnetic Wave Shielding Effectiveness of Carbon Fibers via Chemical Composition Transformation Using H Plasma Treatment.

H plasma treatment was performed on carbon-based nonwoven fabrics (c-NFs) in a 900 W microwave plasma-enhanced chemical vapor deposition system at 750 °C and 40 Torr. Consequently, the electromagnetic wave shielding effectiveness (SE) of the c-NFs was significantly enhanced across the operating frequency range of 0.04 to 20.

Bi and Eu Activated Luminescent Behaviors in Non-Stoichiometric LaOF Structure.

Optical materials composed of LaBiEuOF ( = 0.001-0.05, = 0-0.

Facile synthesis of sub-10 nm-sized bright red-emitting upconversion nanophosphors via tetrahedral YOF:Yb,Er seed-mediated growth.

Ultrasmall and uniform tetrahedral-shaped YOF:Yb,Er upconversion nanophosphors (UCNs) are synthesized and sub-10 nm YOF:Yb,Er/YOF core/shell UCNs are formed via YOF:Yb,Er seed-mediated synthesis. The ultrasmall YOF:Yb,Er/YOF core/shell UCNs realize intense red emission under near infrared light (λ = 980 nm).

Effects of the Carbon Fiber-Carbon Microcoil Hybrid Formation on the Effectiveness of Electromagnetic Wave Shielding on Carbon Fibers-Based Fabrics.

Carbon fiber-carbon microcoil (CF-CMC) hybrids were formed on carbon fiber (CF)-based fabric. The morphologies of CF-based fabrics and CF-CMC hybridized fabrics were investigated. The electrical conductivities of the CF-CMC hybridized fabrics were examined and compared with those of native CF-based fabrics.

Spectral-converting study of Ba((9-3)(m+n)/2)Er(m)Yb(n)Y2Si6O24 (m = 0.005 - 0.2, n = 0 - 0.3) orthosilicate phosphors.

Optical materials composed of Ba((9-3)(m+n)/2)Er(m)Yb(n)Y2Si6O24 (m = 0.005-0.2, n = 0-0.

Near UV excited line and broad band photoluminescence of an anion-ordered oxyfluoride.

A near UV excitable phosphor Sr(2.85)Eu(0.1)Al(0.

EuKNaTaO5: crystal growth, structure and photoluminescence property.

The synthesis, structure determination, and intrinsic luminescent properties of a new tantalate, EuKNaTaO(5), are reported. Single crystals of the title compound were grown out of a reactive KOH/NaOH eutectic melt. Luminescence in many materials is activated by doping a rare earth cation into the solid matrix; we report undoped, all-rare earth EuKNaTaO(5), which exhibits bright orange room temperature photoluminescence.

Synthesis and structure of the bilayer hydrate Na0.3NiO2.1.3D2O.

The metal oxide bilayer deuterate (hydrate) Na(0.3)NiO2.1.