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Eu3+ doped TiO2–SiO2 powders were produced by the sol-gel method. The TiO2 content was changed from low to high content (20–100 mol %) annealing at 900 °C for 1 h, and the 2 mol % Eu3+ doped 60%TiO2–40%SiO2 powders were annealed at different temperatures (600–1000 °C). The structure of the samples was investigated by high resolution transmission electron microscopy, x-ray diffraction, and Raman technique. The photoluminescence (PL) spectra and PL excitation spectra were recorded at room temperature. The results showed that the PL intensity was dependent on the annealing temperatures and TiO2 content, which could be attributed to the cluster formation. [ABSTRACT FROM AUTHOR]

The photoluminescence properties of Tb-doped ZrO2 nanofibers synthesized by electrospinning technique were investigated. The intensity of the green light emission could be controlled by oxygen vacancy concentration, which could be enhanced by argon gas annealing or diminished by oxygen annealing. An energy transfer mechanism is proposed that the oxygen vacancies in the host acted as effective sensitizers for the adjacent Tb ions. The oxygen vacancies transferred excitation energy to the adjacent Tb ions sites and thus greatly enhanced the green emission. These results are of great importance for the future optoelectronic applications of Tb-doped ZrO2 nanofibers. [ABSTRACT FROM AUTHOR]

Abstract: Eu3+-doped β-Ga2O3 nanofibers were fabricated by electrospinning. The influence of Eu3+ concentration on the photoluminescence properties of the obtained nanofibers was investigated. The morphology and structure of β-Ga2O3:Eu3+ were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and Raman spectra. The diameter of the Eu3+-doped β-Ga2O3 nanofibers was in the range of 180–300nm. When the β-Ga2O3:Eu3+ nanofibers were excited by 325nm wavelength, the main emission peak of the samples was 620nm (5D0→7F2), which corresponded to a typical red emission (5D0→7F j (j =1, 2, 3, 4) intra-4f transitions of Eu3+ ions). In addition, the concentration quench effect and energy transfer mechanism in β-Ga2O3:Eu3+ were also discussed. [Copyright &y& Elsevier]

Abstract: Terbium-doped SiCN (SiCN:Tb) films were prepared by radio frequency (rf) reactive sputtering at room temperature (RT) and then annealed in a carbothermal ambience at 800 and 1250°C, respectively. The RT prepared and 1250°C annealed samples have shown blue–green and blue–violet light emissions, respectively; whereas strong green light emissions were observed only from the 800°C annealed samples. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) results revealed that the change of PL properties can be attributed to the evolution of microstructure and chemical compositions of the SiCN films. In addition, photoluminescence excitation (PLE) spectrum indicated that the best PL performance of the 800°C annealed samples might be mainly attributed to the direct band gap (about 3.81eV) of crystalline SiCN. [Copyright &y& Elsevier]