A Ce(3+)-activated fluorosulfide phosphor (β-YFS:Ce(3+)) was synthesized by solid-state reaction in a sealed tube. The crystal structure has been refined from the XRD profiles and there are two different crystallographic rare earth sites, namely, Y(1) and Y(2), where the Ce(3+) ions occupied. The emission band with a maximum at 495 nm of β-Y(0.99)Ce(0.01)FS phosphor was characterized by the 4f-5d transitions of Ce(3+) ion. With increasing Ce(3+) concentration, the emission variations were observed from 495 to 547 nm. When β-YFS:Ce(3+) phosphors were utilized to incorporate with n-UV/blue chip, greenish-white light with color rendering index of 65-77 were obtained. The results indicate that the tunable green- to yellow-emitting β-YFS:Ce(3+) can serve as a potential phosphor for incorporation in fabrication for solid-state lighting. The preparation, spectroscopic characterization, quantum efficiency, thermal-quenching behavior, and related LED device data are also presented.

A series of water-soluble YVO 4 :Bi 3+ ,Eu 3+ nanocrystals, with surfaces functionalized by a branch polyethylenimine (BPEI) polymer, have been synthesized via a one-pot hydrothermal method. It was found that the particle size and crystal morphology could be efficiently controlled by different reaction temperatures, pH values and molecular weights of the BPEI polymer. The surface modification of the nanocrystals was characterized using Fourier transform infrared spectroscopy (FT-IR). The highly crystalline YVO 4 :Bi 3+ ,Eu 3+ nanoparticles, with an average diameter of 20 nm, can be dispersed in water due to the presence of amino ligands. When conjugated with biomolecules, the YVO 4 :Bi 3+ ,Eu 3+ nanocrystals retain their strong red emission, peaking at 619 nm under near-ultraviolet (n-UV) excitation. The results indicate that YVO 4 :Bi 3+ ,Eu 3+ nanocrystals can serve as a promising candidate for biological imaging, and immunoassay applications.

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The commercialization of high-energy-density lithium–sulfur batteries depends on the development of a high-sulfur-loading cathode with high electrochemical utilization and stability in lean-electrolyte cells. However, the desired cell-design parameters often exacerbate...