Guixia Liu

Synthesis of Y2 O3: Eu3+ Hollow Spheres Using Silica as Templates

Abstract The Y2O3:Eu3+ hollow spheres were synthesized using the template-mediated method. XRD patterns indicated that the broadened diffraction peaks resulted from nanocrystals in Y2O3:Eu3+ shells of hollow spheres. XPS spectra showed that the Y2O3:Eu3+ shells were linked with silica cores by a Si-O-Y chemical bond. SEM and TEM observations showed that the size of the SiO2/Y2O3:Eu3+ core-shell particle was about 100 nm, and the thickness of the Y2O3:Eu3+ hollow sphere was less than 5 nm. The photoluminescence spectra of the SiO2/Y2O3:Eu3+ core-shell materials and Y2O3:Eu3+ hollow spheres had red luminescent properties, and the broadened emission peaks came from nanocrystals composed of the Y2O3:Eu3+ shell.

Solvothermal synthesis of Gd2O3:Eu3+ luminescent nanowires

Uniform Gd2O3 : Eu 3+ luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000) as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD) patterns and Fourier transform infrared spectrometry (FTIR) showed that the precursors are hexagonal phase Gd(OH)3 crystals, and the samples calcined at 800◦C are cubic phase Gd2O3. Transmission Electron Microscopy (TEM) images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL) spectra showed that the ratio of D0 → F2 to D0 → F1 transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of the Gd2O3 : Eu 3+ is better than that of the precursors. The as-obtained Gd2O3 : Eu 3+ luminescent nanowires show a strong red emission corresponding to D0 → F2 transition (610 nm) of Eu under ultraviolet excitation (250 nm), which have potential application in red-emitting phosphors and field emission display devices.

Solvothermal Synthesis ofGd2O3 : Eu3+Luminescent Nanowires

Uniform Gd2O3 : Eu 3+ luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000) as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD) patterns and Fourier transform infrared spectrometry (FTIR) showed that the precursors are hexagonal phase Gd(OH)3 crystals, and the samples calcined at 800◦C are cubic phase Gd2O3. Transmission Electron Microscopy (TEM) images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL) spectra showed that the ratio of D0 → F2 to D0 → F1 transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of the Gd2O3 : Eu 3+ is better than that of the precursors. The as-obtained Gd2O3 : Eu 3+ luminescent nanowires show a strong red emission corresponding to D0 → F2 transition (610 nm) of Eu under ultraviolet excitation (250 nm), which have potential application in red-emitting phosphors and field emission display devices.

Solvothermal Synthesis of Luminescent Nanowires

Uniform Gd2O3 : Eu 3+ luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000) as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD) patterns and Fourier transform infrared spectrometry (FTIR) showed that the precursors are hexagonal phase Gd(OH)3 crystals, and the samples calcined at 800◦C are cubic phase Gd2O3. Transmission Electron Microscopy (TEM) images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL) spectra showed that the ratio of D0 → F2 to D0 → F1 transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of the Gd2O3 : Eu 3+ is better than that of the precursors. The as-obtained Gd2O3 : Eu 3+ luminescent nanowires show a strong red emission corresponding to D0 → F2 transition (610 nm) of Eu under ultraviolet excitation (250 nm), which have potential application in red-emitting phosphors and field emission display devices.

Solvothermal synthesis of Gd 2 O 3 : Eu 3+ luminescent nanowires

Uniform Gd2O3 : Eu 3+ luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000) as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD) patterns and Fourier transform infrared spectrometry (FTIR) showed that the precursors are hexagonal phase Gd(OH)3 crystals, and the samples calcined at 800◦C are cubic phase Gd2O3. Transmission Electron Microscopy (TEM) images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL) spectra showed that the ratio of D0 → F2 to D0 → F1 transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of the Gd2O3 : Eu 3+ is better than that of the precursors. The as-obtained Gd2O3 : Eu 3+ luminescent nanowires show a strong red emission corresponding to D0 → F2 transition (610 nm) of Eu under ultraviolet excitation (250 nm), which have potential application in red-emitting phosphors and field emission display devices.

New development of nanocrystalline TiO 2 -based dye-sensitized solar cells

Techniques of dye-sensitized nanocrystalline solar cells(DSSCs) having a conversion efficiency of AM 1.5G solar light to electric power over 11% are reported. In this paper, the fundamental structure and the principle of DSSCs are introduced and the development of key components, including nanoporous semiconductor films, dye sensitizers, electrolyte and counter electrode in DSSCs are reviewed in detail. It is also an interesting aspect where collaboration among different fields of scientists is important to develop the solar cells and to elucidate the mechanism of DSSCs. Further increase of the efficiency is gained by the interdisciplinary research.