Weidong Xiang

Solvothermal Synthesis and Characterization of Zinc Indium Sulfide Microspheres

Znln 2 S 4 microspheres have been solvothermally prepared at 160°C for 12 h with ZnCl 2 ·2H 2 O, lnCl 3 , and thiourea as the starting reagents in ethanol. The morphology, structure, and phase composition of the as-prepared product were characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). Results revealed that the prepared Znln 2 S 4 microspheres were composed of sheetlike nanocrystals. The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm, respectively. A possible growth mechanism of the Znln 2 S 4 nanosheet-built microspheres was proposed and briefly discussed.

Biomolecule-assisted Solvothermal Synthesis of Bismuth Sulfide Nanorods

A simple biomolecule-assisted synthetic route has been successfully developed to prepare bismuth sulfide (Bi2S3) nanorods under solvothermal conditions. In the synthetic system, pentahydrate bismuth nitrate was employed to supply Bi source and L-cystine was used as sulfide source and complexing agent. The morphology, structure, and phase composition of the as-prepared Bi2S3 products were characterized by X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). The experimental results show that the nanorods have uniform diameter of 100-200 nm and length of 2-4 μm. The possible formation mechanism for the bismuth sulfide nanorods was discussed.

A novel green-yellow emitting phosphor Ca1.5Y1.5Al3.5Si1.5O12:Ce3+ and its luminescence properties

Abstract We described the synthesis and luminescence of Ca 1.5 Y 1.5 Al 3.5 Si 1.5 O 12 :Ce 3+ phosphor for light emitting diode (LED). The crystallinity, morphology, structure, and luminescence spectra were examined by X-ray diffraction, field emission-scanning electron microscopy and photoluminescence spectroscopy. The results showed that Ca 1.5 Y 1.5 Al 3.5 Si 1.5 O 12 :Ce 3+ phase was a dominating phase with little impurity phase peaks of Y 2 O 3 when the sintered temperature reached to 1400°C. Field emission scanning electron microscopy (FE-SEM) images showed the particle size of the phosphor was about 3 μm. Meanwhile, the excitation and emission spectra indicated that the as-prepared phosphors could be effectively excited by blue (460 nm) light and the excitation spectrum showed a broad band extending from 400–500 nm, while emission spectrum showed a broad yellow band peaking at 534 nm. The decay curve at the emission peak consisted of fast and slow components. The Ca 1.5 Y 1.5 Al 3.5 Si 1.5 O 12 :Ce 3+ should be a promising yellow phosphor for near blue-based white-light-emitting diodes (LEDs).